Pub Date : 2026-02-01Epub Date: 2026-02-13DOI: 10.1016/j.jtherbio.2026.104411
Carmen Rolandi , Silvina A. Belliard , Pablo E. Schilman
Environmental temperature strongly influences insect metabolic rate (MR), yet the thermal sensitivity of MR across developmental stages remains understudied in hemimetabolous species. Here we quantified resting metabolic rate (RMR) thermal sensitivity in Rhodnius prolixus, a hemimetabolous insect and an important Chagas disease vector. For that, we measured real-time CO2 production by open flow-respirometry as a proxy for MR at six temperatures (10, 15, 20, 25, 30, and 35 °C) across all life stages. We found a stage-specific thermal sensitivity of the RMR. Instantaneous Q10 estimates revealed ontogenetic variation: early nymphs exhibited higher thermal sensitivity at cooler temperatures and lower sensitivity at warmer temperatures, while adults maintained constant Q10 values across the thermal range. These findings provide novel insights into thermal biology of hemimetabolous insects and show that developmental stage influences metabolic responses to temperature. Understanding these patterns is crucial for predicting how climate warming may affect the physiology, population dynamics and disease transmission potential of this vector species.
{"title":"Thermal sensitivity of metabolic rate in a hemimetabolous insect: variation across life stages","authors":"Carmen Rolandi , Silvina A. Belliard , Pablo E. Schilman","doi":"10.1016/j.jtherbio.2026.104411","DOIUrl":"10.1016/j.jtherbio.2026.104411","url":null,"abstract":"<div><div>Environmental temperature strongly influences insect metabolic rate (MR), yet the thermal sensitivity of MR across developmental stages remains understudied in hemimetabolous species. Here we quantified resting metabolic rate (RMR) thermal sensitivity in <em>Rhodnius prolixus</em>, a hemimetabolous insect and an important Chagas disease vector. For that, we measured real-time CO<sub>2</sub> production by open flow-respirometry as a proxy for MR at six temperatures (10, 15, 20, 25, 30, and 35 °C) across all life stages. We found a stage-specific thermal sensitivity of the RMR. Instantaneous Q<sub>10</sub> estimates revealed ontogenetic variation: early nymphs exhibited higher thermal sensitivity at cooler temperatures and lower sensitivity at warmer temperatures, while adults maintained constant Q<sub>10</sub> values across the thermal range. These findings provide novel insights into thermal biology of hemimetabolous insects and show that developmental stage influences metabolic responses to temperature. Understanding these patterns is crucial for predicting how climate warming may affect the physiology, population dynamics and disease transmission potential of this vector species.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104411"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146257527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-02-03DOI: 10.1016/j.jtherbio.2026.104403
Marek Sokol , Petr Volf , Jakub Holuša , Michael Matějka , Jan Hejda , Patrik Kutílek
Human sleep is strongly influenced by thermoregulatory and circadian processes, both of which are challenged in polar environments characterized by continuous daylight, low ambient temperatures, and high variability in solar radiation. This study examined how thermal and photic conditions modulate sleep architecture and autonomic function during the 2025 Czech Antarctic Expedition at James Ross Island. Ten expedition members were continuously monitored using validated wearable sensors that recorded sleep stages, heart rate, and respiratory rate across pre-expedition, Antarctic, and post-expedition phases. Environmental variables, including air temperature, relative humidity, and global radiation, were concurrently logged indoors and outdoors. Linear mixed-effects models revealed that the Antarctic phase was associated with a significant increase in slow-wave sleep (17.8 4.1% pre-expedition vs. 20.2 4.3% during expedition, ) and a decrease in light sleep (). Higher outdoor temperatures predicted a greater proportion of deep sleep (, ), and lower humidity was associated with increased deep sleep (, ). The resting heart rate rose during the expedition and then declined significantly afterward, indicating autonomic recovery. These findings suggest that human sleep exhibits adaptive reorganization under combined thermal and photic stress, with enhanced slow-wave sleep supporting physiological restoration in cold, high-variability environments. The results provide novel evidence of thermoregulatory coupling between environmental conditions, sleep architecture, and autonomic balance in situ.
{"title":"Thermal and photic modulation of human sleep architecture and autonomic adaptation during an Antarctic summer expedition","authors":"Marek Sokol , Petr Volf , Jakub Holuša , Michael Matějka , Jan Hejda , Patrik Kutílek","doi":"10.1016/j.jtherbio.2026.104403","DOIUrl":"10.1016/j.jtherbio.2026.104403","url":null,"abstract":"<div><div>Human sleep is strongly influenced by thermoregulatory and circadian processes, both of which are challenged in polar environments characterized by continuous daylight, low ambient temperatures, and high variability in solar radiation. This study examined how thermal and photic conditions modulate sleep architecture and autonomic function during the 2025 Czech Antarctic Expedition at James Ross Island. Ten expedition members were continuously monitored using validated wearable sensors that recorded sleep stages, heart rate, and respiratory rate across pre-expedition, Antarctic, and post-expedition phases. Environmental variables, including air temperature, relative humidity, and global radiation, were concurrently logged indoors and outdoors. Linear mixed-effects models revealed that the Antarctic phase was associated with a significant increase in slow-wave sleep (17.8 <span><math><mo>±</mo></math></span> 4.1% pre-expedition vs. 20.2 <span><math><mo>±</mo></math></span> 4.3% during expedition, <span><math><mrow><mi>p</mi><mo><</mo><mn>0</mn><mo>.</mo><mn>001</mn></mrow></math></span>) and a decrease in light sleep (<span><math><mrow><mi>p</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>002</mn></mrow></math></span>). Higher outdoor temperatures predicted a greater proportion of deep sleep (<span><math><mrow><mi>β</mi><mo>=</mo><mn>2</mn><mo>.</mo><mn>00</mn></mrow></math></span>, <span><math><mrow><mi>p</mi><mo><</mo><mn>0</mn><mo>.</mo><mn>001</mn></mrow></math></span>), and lower humidity was associated with increased deep sleep (<span><math><mrow><mi>β</mi><mo>=</mo><mo>−</mo><mn>1</mn><mo>.</mo><mn>04</mn></mrow></math></span>, <span><math><mrow><mi>p</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>046</mn></mrow></math></span>). The resting heart rate rose during the expedition and then declined significantly afterward, indicating autonomic recovery. These findings suggest that human sleep exhibits adaptive reorganization under combined thermal and photic stress, with enhanced slow-wave sleep supporting physiological restoration in cold, high-variability environments. The results provide novel evidence of thermoregulatory coupling between environmental conditions, sleep architecture, and autonomic balance <em>in situ</em>.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104403"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146125446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-17DOI: 10.1016/j.jtherbio.2026.104383
Benoit Mauvieux , Adrian Markov , Stéphane Besnard , Yvan Touitou , Ben J. Edwards
Firefighters are repeatedly exposed to extreme radiant and convective heat during live-fire training, yet the potential influence of circadian timing on their thermoregulatory tolerance remains unexplored. This study tested whether time-of-day modulates physiological strain during standardized container fire exposures. Twenty-one professional male firefighters completed two identical 40-min live-fire sessions on the same day: late-morning (09:00 h, heat-gain phase) and late-evening (21:30 h, heat-loss phase). Core temperature (ingestible sensor), heart rate, skin temperature, under-PPE temperature and humidity, body mass, total body water, and ratings of perceived exertion were recorded. Environmental conditions were strictly matched between sessions. Core temperature rose faster and higher in the morning (ΔTcore +1.10 ± 0.25 °C; slope 0.028 °C·min−1) than in the evening (+0.49 ± 0.21 °C; 0.012 °C·min−1), despite similar peak values. Post-exposure cooling was slower in the morning (−0.37 vs −0.63 °C·h−1), with a delayed hypothermic rebound. Morning sessions also elicited higher heart rates, greater perceived exertion, larger body-mass and water losses, and higher sub-garment humidity. These findings demonstrate that circadian phase significantly influences heat storage and recovery, with late-morning exposures imposing greater thermophysiological strain under identical workloads. Incorporating chronobiological principles into firefighter training schedules may reduce heat-related risk and optimize recovery strategies in extreme environments.
{"title":"Circadian modulation of core temperature and thermoregulatory strain during live-fire compartment exposure in firefighters","authors":"Benoit Mauvieux , Adrian Markov , Stéphane Besnard , Yvan Touitou , Ben J. Edwards","doi":"10.1016/j.jtherbio.2026.104383","DOIUrl":"10.1016/j.jtherbio.2026.104383","url":null,"abstract":"<div><div>Firefighters are repeatedly exposed to extreme radiant and convective heat during live-fire training, yet the potential influence of circadian timing on their thermoregulatory tolerance remains unexplored. This study tested whether time-of-day modulates physiological strain during standardized container fire exposures. Twenty-one professional male firefighters completed two identical 40-min live-fire sessions on the same day: late-morning (09:00 h, heat-gain phase) and late-evening (21:30 h, heat-loss phase). Core temperature (ingestible sensor), heart rate, skin temperature, under-PPE temperature and humidity, body mass, total body water, and ratings of perceived exertion were recorded. Environmental conditions were strictly matched between sessions. Core temperature rose faster and higher in the morning (ΔTcore +1.10 ± 0.25 °C; slope 0.028 °C·min<sup>−1</sup>) than in the evening (+0.49 ± 0.21 °C; 0.012 °C·min<sup>−1</sup>), despite similar peak values. Post-exposure cooling was slower in the morning (−0.37 vs −0.63 °C·h<sup>−1</sup>), with a delayed hypothermic rebound. Morning sessions also elicited higher heart rates, greater perceived exertion, larger body-mass and water losses, and higher sub-garment humidity. These findings demonstrate that circadian phase significantly influences heat storage and recovery, with late-morning exposures imposing greater thermophysiological strain under identical workloads. Incorporating chronobiological principles into firefighter training schedules may reduce heat-related risk and optimize recovery strategies in extreme environments.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104383"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-21DOI: 10.1016/j.jtherbio.2026.104398
Hangyu Lin , Xiaoyun Wu , Ya Liu , Jun Ou , Luyun Ni , Feiyang Li , Jiansheng Lai , Quan Gong , Jue Lin , MingJiang Song
Global warming alters aquatic habitats, challenging cold-water fish survival. Schizopygopsis chengi baoxingensis, a cold-water fish from the Qingyijiang River in China, is vulnerable to temperature changes. This study aimed to elucidate the molecular mechanisms underlying the response of S. c. baoxingensis to acute heat stress through an integrated approach of histopathological, transcriptomic, and metabolomic analyses. Histopathological results revealed significant tissue damage in both the liver and gills, with the liver showing pronounced hepatocellular vacuolization and nuclear displacement, and the gills exhibiting hyperplasia and partial lamellar necrosis. Transcriptomic analysis identified numerous differentially expressed genes (DEGs) in both tissues. In the liver, DEGs were enriched in pathways related to antioxidant stress, detoxification, and immune response. Notably, genes encoding glutathione S-transferase (GST) and UDP-glucuronosyltransferase (UGT) were upregulated, suggesting enhanced antioxidant and detoxification capabilities. Additionally, immune-related genes such as C2, C3, C4, C6, C9, CFB, CFH, and MASP2 were predominantly upregulated in the complement and coagulation cascades pathway. In the gills, DEGs including NPNT and NOS2 were significantly upregulated, suggesting enhanced respiratory function. Metabolomic profiling showed significant alterations in energy metabolism, with increased levels of NAD and NADH in the liver, indicating heightened energy demands under thermal stress. Our findings provide valuable insights into the molecular mechanisms underlying the heat stress response of S. c. baoxingensis and highlight potential targets for protecting this species under climate change.
{"title":"Integrated transcriptomic and metabolomic analyses reveal the molecular adaptive mechanisms of Schizopygopsis chengi baoxingensis under acute heat stress","authors":"Hangyu Lin , Xiaoyun Wu , Ya Liu , Jun Ou , Luyun Ni , Feiyang Li , Jiansheng Lai , Quan Gong , Jue Lin , MingJiang Song","doi":"10.1016/j.jtherbio.2026.104398","DOIUrl":"10.1016/j.jtherbio.2026.104398","url":null,"abstract":"<div><div>Global warming alters aquatic habitats, challenging cold-water fish survival. <em>Schizopygopsis chengi baoxingensis</em>, a cold-water fish from the Qingyijiang River in China, is vulnerable to temperature changes. This study aimed to elucidate the molecular mechanisms underlying the response of <em>S. c. baoxingensis</em> to acute heat stress through an integrated approach of histopathological, transcriptomic, and metabolomic analyses. Histopathological results revealed significant tissue damage in both the liver and gills, with the liver showing pronounced hepatocellular vacuolization and nuclear displacement, and the gills exhibiting hyperplasia and partial lamellar necrosis. Transcriptomic analysis identified numerous differentially expressed genes (DEGs) in both tissues. In the liver, DEGs were enriched in pathways related to antioxidant stress, detoxification, and immune response. Notably, genes encoding glutathione S-transferase (GST) and UDP-glucuronosyltransferase (UGT) were upregulated, suggesting enhanced antioxidant and detoxification capabilities. Additionally, immune-related genes such as C2, C3, C4, C6, C9, CFB, CFH, and MASP2 were predominantly upregulated in the complement and coagulation cascades pathway. In the gills, DEGs including NPNT and NOS2 were significantly upregulated, suggesting enhanced respiratory function. Metabolomic profiling showed significant alterations in energy metabolism, with increased levels of NAD and NADH in the liver, indicating heightened energy demands under thermal stress. Our findings provide valuable insights into the molecular mechanisms underlying the heat stress response of <em>S. c. baoxingensis</em> and highlight potential targets for protecting this species under climate change.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104398"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the effect of prewarming (PD) and thermal manipulation (TM) of long-stored eggs on embryonic development, hatching traits, body weight (BW), rectal temperature (RT), carcass, and organ traits in broilers at 3 days of age (DOA). Hatching eggs were exposed 2 PD treatments (6 h and 9-h) after storage. Each PD treatment was further divided into 2 groups and either incubated with a standard temperature (SI, 37.5 °C) or exposed to high temperature (TM, 39 °C between ED 5 and 17). Therefore, four experimental treatments in a completely randomized design (2 × 2 factorial experimental design) were created as follows: Eggs exposed to 6-h prewarming duration + standard incubation temperature (6-PDSI), eggs exposed to 9-h prewarming duration + standard incubation temperature (9-PDSI), eggs exposed to 6-h prewarming + high incubation temperature (6-PDTM) and eggs exposed to 9-h prewarming + high incubation temperature (9-PDTM). The incubation temperature (INC-T) had no significant effect on egg weight (EW) and egg weight loss (EW-L) (P>0.05). The PD only influenced the Ew-L at embryonic day (ED) 10, which was higher in eggs preheated for 6 h (6-PD) than in eggs preheated for 9 h (9-PD) (P<0.05). The weight of yolk-free body mass (YFBM-w), embryo length (Em-L), and beak length (BL) at ED 15 and the embryo + yolk weight (W-EY), YFBM-w, Em-L, tibia length (TL), and BL at ED 18 were higher in the 6-PD than in the 9-PD (P<0.05). The Embryo + yolk yield (EY-Y), YFBM-w, yield of the yolk-free body mass (YFBM-Y), and Em-L at ED 15 and the W-EY, YFBM-w, and Em-L at ED 18 were significantly higher in TM than in SI embryos (P<0.05). However, the eye width (Ey-w) at ED 15 was higher in the SI than in the TM embryos (P<0.05). The INC-T and PD had no significant effect on hatchability, embryonic mortality, chick weight, and chick yield (P>0.05). However, the chick length was higher in the SI chicks (P<0.05). The body weight, heart, liver, thigh, and intestinal traits were higher in 9-PD chicks, while rectal temperature was lowest in 6-PD chicks (P<0.05). The thigh yield (TH-y) was higher in the TM than in the SI chicks (P<0.05).
本试验研究了保温和热处理对3日龄肉仔鸡胚胎发育、孵化性状、体重、直肠温度、胴体和器官性状的影响。孵卵存放后分别用PD处理6 h和9 h。每个PD处理进一步分为2组，分别在标准温度（SI, 37.5°C）和高温（TM, 39°C， ED 5至17）下孵育。因此，采用完全随机设计（2 × 2因子试验设计）设计4个试验处理，分别为：预热6 h +标准孵育温度（6-PDSI）、预热9 h +标准孵育温度（9-PDSI）、预热6 h +高孵育温度（6-PDTM）和预热9 h +高孵育温度（9-PDTM）。孵育温度（INC-T）对蛋重（EW）和蛋重损失（EW- l）无显著影响（P>0.05）。PD仅影响胚胎日（ED） 10时的Ew-L，且预热6 h （6-PD）的Ew-L高于预热9 h （9-PD）的Ew-L （P<0.05）。育龄15时无蛋黄体质量（YFBM-w）、胚长（Em-L）、喙长（BL）和育龄18时胚+蛋黄重（W-EY）、YFBM-w、Em-L、胫骨长（TL）、BL均高于育龄9时（p < 0.05）。第15期的胚+蛋黄产量（EY-Y）、YFBM-w、无蛋黄体质量产量（YFBM-Y）和Em-L以及第18期的W-EY、YFBM-w和Em-L显著高于SI胚（P<0.05）。然而，胚胎发育15时，SI胚胎的眼宽（Ey-w）高于TM胚胎（P<0.05）。INC-T和PD对孵化率、胚胎死亡率、雏鸡体重和雏鸡产量无显著影响（P>0.05）。但SI组雏鸡的鸡长高于对照组（P<0.05）。9-PD雏鸡的体重、心脏、肝脏、大腿和肠道性状最高，6-PD雏鸡的直肠温度最低（p < 0.05）。TM组的大腿产量（TH-y）高于SI组（p < 0.05）。
{"title":"Prewarming and thermal manipulation of long stored eggs: effect on embryonic development, hatching traits, body weight, rectal temperature, carcass, and organ traits at 3 days of age in broiler chickens","authors":"Nasir Abdallah , Mikail Baylan , Kadriye Kursun , Gulsen Copur Akpinar","doi":"10.1016/j.jtherbio.2026.104407","DOIUrl":"10.1016/j.jtherbio.2026.104407","url":null,"abstract":"<div><div>This study investigated the effect of prewarming (PD) and thermal manipulation (TM) of long-stored eggs on embryonic development, hatching traits, body weight (BW), rectal temperature (RT), carcass, and organ traits in broilers at 3 days of age (DOA). Hatching eggs were exposed 2 PD treatments (6 h and 9-h) after storage. Each PD treatment was further divided into 2 groups and either incubated with a standard temperature (SI, 37.5 °C) or exposed to high temperature (TM, 39 °C between ED 5 and 17). Therefore, four experimental treatments in a completely randomized design (2 × 2 factorial experimental design) were created as follows: Eggs exposed to 6-h prewarming duration + standard incubation temperature (6-PDSI), eggs exposed to 9-h prewarming duration + standard incubation temperature (9-PDSI), eggs exposed to 6-h prewarming + high incubation temperature (6-PDTM) and eggs exposed to 9-h prewarming + high incubation temperature (9-PDTM). The incubation temperature (INC-T) had no significant effect on egg weight (EW) and egg weight loss (EW-L) (<em>P>0.05</em>). The PD only influenced the Ew-L at embryonic day (ED) 10, which was higher in eggs preheated for 6 h (6-PD) than in eggs preheated for 9 h (9-PD) (<em>P<0.05</em>). The weight of yolk-free body mass (YFBM-w), embryo length (Em-L), and beak length (BL) at ED 15 and the embryo + yolk weight (W-EY), YFBM-w, Em-L, tibia length (TL), and BL at ED 18 were higher in the 6-PD than in the 9-PD (<em>P<0.05</em>). The Embryo + yolk yield (EY-Y), YFBM-w, yield of the yolk-free body mass (YFBM-Y), and Em-L at ED 15 and the W-EY, YFBM-w, and Em-L at ED 18 were significantly higher in TM than in SI embryos (<em>P<0.05</em>). However, the eye width (Ey-w) at ED 15 was higher in the SI than in the TM embryos (<em>P<0.05</em>). The INC-T and PD had no significant effect on hatchability, embryonic mortality, chick weight, and chick yield (<em>P>0.05</em>)<strong>.</strong> However, the chick length was higher in the SI chicks (<em>P<0.05</em>). The body weight, heart, liver, thigh, and intestinal traits were higher in 9-PD chicks, while rectal temperature was lowest in 6-PD chicks (<em>P<0.05</em>). The thigh yield (TH-y) was higher in the TM than in the SI chicks (<em>P<0.05</em>).</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104407"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146170256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-02-11DOI: 10.1016/j.jtherbio.2026.104420
Jakob Wiil, Natalie Pilakouta
Environmental temperature is a key determinant of fitness, influencing survival, reproduction, activity and behaviour. With climate change increasing the frequency and intensity of extreme thermal events, it is crucial to understand the capacity of organisms to adapt to a new thermal reality. While the impacts of acute thermal stress on physiological traits are well-documented, less is known about the ontogenetic effects of such extreme events, particularly regarding how they interact with complex behavioural mechanisms like parental care. Here, we investigated how exposure to a heatwave during the larval stage influences adult reproductive success and parental care in the burying beetle Nicrophorus vespilloides. Larvae were exposed to a simulated heatwave (26 °C for 72 h) or maintained under control conditions (20 °C). We then assessed reproductive and behavioural outcomes in adulthood, along with downstream effects on offspring fitness. We found that larvae exposed to a heatwave suffered a significant reduction in survival to adulthood. However, for individuals that survived, there was no significant effect on their reproductive success, the amount of parental care provided to their offspring, or their offspring's fitness. These findings offer a nuanced perspective on the prevailing assumption that fertility and reproductive behaviour are more sensitive to thermal stress than survival. Our results underscore the need to consider stage-specific and trait-specific responses when evaluating the biological impacts of climate extremes and highlight the complexity of thermal resilience in ectotherm life histories.
{"title":"Early-life thermal stress reduces survival but has no long-term effects on reproduction in an insect","authors":"Jakob Wiil, Natalie Pilakouta","doi":"10.1016/j.jtherbio.2026.104420","DOIUrl":"10.1016/j.jtherbio.2026.104420","url":null,"abstract":"<div><div>Environmental temperature is a key determinant of fitness, influencing survival, reproduction, activity and behaviour. With climate change increasing the frequency and intensity of extreme thermal events, it is crucial to understand the capacity of organisms to adapt to a new thermal reality. While the impacts of acute thermal stress on physiological traits are well-documented, less is known about the ontogenetic effects of such extreme events, particularly regarding how they interact with complex behavioural mechanisms like parental care. Here, we investigated how exposure to a heatwave during the larval stage influences adult reproductive success and parental care in the burying beetle <em>Nicrophorus vespilloides</em>. Larvae were exposed to a simulated heatwave (26 °C for 72 h) or maintained under control conditions (20 °C). We then assessed reproductive and behavioural outcomes in adulthood, along with downstream effects on offspring fitness. We found that larvae exposed to a heatwave suffered a significant reduction in survival to adulthood. However, for individuals that survived, there was no significant effect on their reproductive success, the amount of parental care provided to their offspring, or their offspring's fitness. These findings offer a nuanced perspective on the prevailing assumption that fertility and reproductive behaviour are more sensitive to thermal stress than survival. Our results underscore the need to consider stage-specific and trait-specific responses when evaluating the biological impacts of climate extremes and highlight the complexity of thermal resilience in ectotherm life histories.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104420"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146170325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-02-09DOI: 10.1016/j.jtherbio.2026.104418
Fei Song , Binglin Wang , Xin Kang , Aige Han , Huiyuan Rui , Xiangyang Xu , Yi Guo , Ming Ge , Xiaowen Jiang , Wenhui Yu
Heat stress (HS) induces a metabolic slowdown that impairs growth in livestock and poultry. The present study sought to examine the function and underlying mechanisms of melatonin (MT) in mitigating lipid metabolism disorders caused by HS in broiler chickens. Sixty Shengnong 901 broiler chickens were randomly divided into six groups (n = 10), including a control group, a high-dose MT intervention control group (2.0 mg/kg body weight), HS group, and MT low-dose (0.5 mg/kg body weight), medium-dose (1.0 mg/kg body weight), and high-dose (2.0 mg/kg body weight) MT intervention groups. Combining in vivo experiments with network pharmacology analysis, this study elucidates the mechanism by which MT alleviates HS-induced metabolic slowdown affecting broiler growth through regulation of lipid metabolism. The findings indicated that melatonin supplementation markedly enhanced the growth performance of broilers subjected to heat stress. Compared to the HS group, the HSL, HSM, and HSH groups exhibited reduced serum T-CHO, TG, GLU, and LDL levels (P < 0.05), along with decreased hepatic lipid deposition and oxidative damage, indicating MT's capacity to enhance hepatic lipid metabolism under HS conditions. Network pharmacology screening revealed that MT regulates key lipid metabolism targets via the AMPK/PPARα signaling axis. RT-qPCR data demonstrated a significant increase in AMPKα and PPARα expression in the HSM group compared to the HS group (P < 0.01), while key genes in the SREBP1/FASN pathway were downregulated. The study indicates that MT promotes fatty acid oxidation by activating the AMPK/PPARα signaling pathway while simultaneously inhibiting lipid synthesis mediated by SREBP1/FASN, thereby improving hepatic lipid accumulation induced by HS. In conclusion, MT at 1.0 mg/kg body weight is the optimal intervention dose, effectively improving lipid metabolism disorders through multi-target regulation, providing a theoretical basis and practical reference for enhancing poultry resistance to HS.
{"title":"Exogenous melatonin alleviates heat stress-induced metabolic slowdown affecting broiler growth by improving lipid metabolism","authors":"Fei Song , Binglin Wang , Xin Kang , Aige Han , Huiyuan Rui , Xiangyang Xu , Yi Guo , Ming Ge , Xiaowen Jiang , Wenhui Yu","doi":"10.1016/j.jtherbio.2026.104418","DOIUrl":"10.1016/j.jtherbio.2026.104418","url":null,"abstract":"<div><div>Heat stress (HS) induces a metabolic slowdown that impairs growth in livestock and poultry. The present study sought to examine the function and underlying mechanisms of melatonin (MT) in mitigating lipid metabolism disorders caused by HS in broiler chickens. Sixty Shengnong 901 broiler chickens were randomly divided into six groups (n = 10), including a control group, a high-dose MT intervention control group (2.0 mg/kg body weight), HS group, and MT low-dose (0.5 mg/kg body weight), medium-dose (1.0 mg/kg body weight), and high-dose (2.0 mg/kg body weight) MT intervention groups. Combining in vivo experiments with network pharmacology analysis, this study elucidates the mechanism by which MT alleviates HS-induced metabolic slowdown affecting broiler growth through regulation of lipid metabolism. The findings indicated that melatonin supplementation markedly enhanced the growth performance of broilers subjected to heat stress. Compared to the HS group, the HSL, HSM, and HSH groups exhibited reduced serum T-CHO, TG, GLU, and LDL levels <em>(P < 0.05)</em>, along with decreased hepatic lipid deposition and oxidative damage, indicating MT's capacity to enhance hepatic lipid metabolism under HS conditions. Network pharmacology screening revealed that MT regulates key lipid metabolism targets via the AMPK/PPARα signaling axis. RT-qPCR data demonstrated a significant increase in AMPKα and PPARα expression in the HSM group compared to the HS group <em>(P < 0.01)</em>, while key genes in the SREBP1/FASN pathway were downregulated. The study indicates that MT promotes fatty acid oxidation by activating the AMPK/PPARα signaling pathway while simultaneously inhibiting lipid synthesis mediated by SREBP1/FASN, thereby improving hepatic lipid accumulation induced by HS. In conclusion, MT at 1.0 mg/kg body weight is the optimal intervention dose, effectively improving lipid metabolism disorders through multi-target regulation, providing a theoretical basis and practical reference for enhancing poultry resistance to HS.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104418"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146170326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-22DOI: 10.1016/j.jtherbio.2026.104400
Jiangnan Yao , Pin Fang , Haiyan Zhang , Ping Liu , Xiaoqiong Jiang , Pan Huang , Fuman Cai
Background
Skin flap necrosis is a common complication after breast cancer surgery, affecting postoperative recovery and subsequent treatment. Current assessment methods are often subjective or expensive. This study explored the use of infrared thermal imaging (IRT) for early, non-invasive, and real-time prediction of skin flap necrosis.
Method
A total of 203 breast cancer patients were followed for five days after surgery. Skin temperature was measured daily using a portable infrared camera. The temperature difference (ΔT) between the skin flap and a control area was calculated. Receiver operating characteristic curves were used to evaluate the predictive performance of IRT. Kaplan–Meier analysis and Cox proportional hazards regression were applied to assess the association between skin temperature and the risk of skin flap necrosis. A joint prediction model incorporating clinical baseline variables and temperature indicators was visualized using nomograms.
Results
The incidence of skin flap necrosis was 10.84 %. ΔT was significantly associated with the risk of necrosis, with the strongest predictive value observed on postoperative day 5. A ΔT ≥ 0.7 °C was identified as a key indicator. The high-risk group had a 7.6 - fold higher risk of necrosis than the low-risk group. Age, nulliparity, smoking, and tumor pathology were independent risk factors. Incorporation of postoperative flap temperature indicators significantly improved the predictive performance of the model.
Conclusion
IRT provides a non-contact method for assessing postoperative skin flap blood flow and metabolism. ΔT, particularly on postoperative days 4 and 5, is a significant predictor of skin flap necrosis risk.
{"title":"Infrared thermal imaging as a non-invasive predictive tool for early detection of flap necrosis after breast cancer surgery: A prospective cohort study","authors":"Jiangnan Yao , Pin Fang , Haiyan Zhang , Ping Liu , Xiaoqiong Jiang , Pan Huang , Fuman Cai","doi":"10.1016/j.jtherbio.2026.104400","DOIUrl":"10.1016/j.jtherbio.2026.104400","url":null,"abstract":"<div><h3>Background</h3><div>Skin flap necrosis is a common complication after breast cancer surgery, affecting postoperative recovery and subsequent treatment. Current assessment methods are often subjective or expensive. This study explored the use of infrared thermal imaging (IRT) for early, non-invasive, and real-time prediction of skin flap necrosis.</div></div><div><h3>Method</h3><div>A total of 203 breast cancer patients were followed for five days after surgery. Skin temperature was measured daily using a portable infrared camera. The temperature difference (ΔT) between the skin flap and a control area was calculated. Receiver operating characteristic curves were used to evaluate the predictive performance of IRT. Kaplan–Meier analysis and Cox proportional hazards regression were applied to assess the association between skin temperature and the risk of skin flap necrosis. A joint prediction model incorporating clinical baseline variables and temperature indicators was visualized using nomograms.</div></div><div><h3>Results</h3><div>The incidence of skin flap necrosis was 10.84 %. ΔT was significantly associated with the risk of necrosis, with the strongest predictive value observed on postoperative day 5. A ΔT ≥ 0.7 °C was identified as a key indicator. The high-risk group had a 7.6 - fold higher risk of necrosis than the low-risk group. Age, nulliparity, smoking, and tumor pathology were independent risk factors. Incorporation of postoperative flap temperature indicators significantly improved the predictive performance of the model.</div></div><div><h3>Conclusion</h3><div>IRT provides a non-contact method for assessing postoperative skin flap blood flow and metabolism. ΔT, particularly on postoperative days 4 and 5, is a significant predictor of skin flap necrosis risk.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104400"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Corrigendum to “Treatment of accidental hypothermia: Impact of insulation placement above or below an active external rewarming device on temperature and burn risk” [J. Therm. Biol. (129), 2025, 104126]","authors":"Sigurd Mydske , Guttorm Brattebø , Ane Marthe Helland , Øystein Wiggen , Jörg Assmus , Øyvind Thomassen","doi":"10.1016/j.jtherbio.2026.104368","DOIUrl":"10.1016/j.jtherbio.2026.104368","url":null,"abstract":"","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104368"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145952484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-22DOI: 10.1016/j.jtherbio.2026.104390
Danilo Giacometti , Luis F. Montes , Melanie Denommé , Denis V. Andrade , Glenn J. Tattersall
Accurately measuring body temperature is critical for understanding how ectotherms interact with their thermal environment. In amphibians, traditional methods like cloacal thermometry require restraint, potentially altering body temperature through stress and heat transfer from human hands. Here, we used infrared thermography to examine how short-term gentle handling (2 min) impacted skin temperatures (Tskin) in two species of mole salamanders (Ambystoma laterale and A. maculatum) by combining field and lab experiments. In the field, we randomly assigned salamanders to a handled or control group, whereas in the lab salamanders were assigned to a heating plate set to hand temperature or a control group. We also scored salamander activity (active vs. inactive) in both settings. In the field, handling increased Tskin in both species, with the head warming up more than the dorsum. Moreover, A. laterale experienced an overall greater magnitude of thermal change (ΔTskin) than A. maculatum due to body size differences. In the lab, contact with the heating plate increased Tskin, with head Tskin being consistently warmer than dorsal Tskin. We also found that ΔTskin was greater for the handled than the heating plate group (ΔTskin = 4.86 ± 1.21 °C vs. 1.72 ± 0.70 °C, respectively), suggesting that handling may amplify heat gain. Warmer salamanders were more prone to be active regardless of whether they were handled or in contact with a heating plate. Our results demonstrate that short-term handling can cause rapid warming that exceeds rates used in heat stress studies, with implications for data reliability and amphibian welfare in thermal biology assays.
准确测量体温对于了解变温动物如何与热环境相互作用至关重要。在两栖动物中，像肛管测温这样的传统方法需要限制，可能会通过人类双手的压力和热量传递来改变体温。本研究采用红外热像仪，结合野外和实验室实验，研究了两种鼹鼠蝾螈（Ambystoma laterale和A. maculatum）的短期温和处理（2分钟）对皮肤温度（Tskin）的影响。在野外，我们随机将蝾螈分配到一个有手的组或对照组，而在实验室里，蝾螈被分配到一个加热板上，设置手的温度或一个对照组。我们还对两种情况下蝾螈的活动（活跃与不活跃）进行了评分。在野外，这两个物种的Tskin都增加了，头部比背部更暖和。此外，由于体型差异，侧边刺比斑纹刺经历了更大的总体热变化（ΔTskin）。在实验室中，与加热板的接触增加了Tskin，头部Tskin始终比背部Tskin温暖。我们还发现，与加热板组相比，处理组的ΔTskin温度更高（ΔTskin = 4.86±1.21°C vs. 1.72±0.70°C），这表明处理可能会放大热量增益。无论它们是否被处理或接触加热板，温暖的蝾螈都更容易活跃。我们的研究结果表明，短期处理可能导致快速变暖，超过热应激研究中使用的速率，这对热生物学分析中的数据可靠性和两栖动物福利有影响。
{"title":"Handle with care: the thermal consequences of short-term handling in mole salamanders","authors":"Danilo Giacometti , Luis F. Montes , Melanie Denommé , Denis V. Andrade , Glenn J. Tattersall","doi":"10.1016/j.jtherbio.2026.104390","DOIUrl":"10.1016/j.jtherbio.2026.104390","url":null,"abstract":"<div><div>Accurately measuring body temperature is critical for understanding how ectotherms interact with their thermal environment. In amphibians, traditional methods like cloacal thermometry require restraint, potentially altering body temperature through stress and heat transfer from human hands. Here, we used infrared thermography to examine how short-term gentle handling (2 min) impacted skin temperatures (<em>T</em><sub>skin</sub>) in two species of mole salamanders (<em>Ambystoma laterale</em> and <em>A</em>. <em>maculatum</em>) by combining field and lab experiments. In the field, we randomly assigned salamanders to a handled or control group, whereas in the lab salamanders were assigned to a heating plate set to hand temperature or a control group. We also scored salamander activity (active vs. inactive) in both settings. In the field, handling increased <em>T</em><sub>skin</sub> in both species, with the head warming up more than the dorsum. Moreover, <em>A</em>. <em>laterale</em> experienced an overall greater magnitude of thermal change (Δ<em>T</em><sub>skin</sub>) than <em>A</em>. <em>maculatum</em> due to body size differences. In the lab, contact with the heating plate increased <em>T</em><sub>skin</sub>, with head <em>T</em><sub>skin</sub> being consistently warmer than dorsal <em>T</em><sub>skin</sub>. We also found that Δ<em>T</em><sub>skin</sub> was greater for the handled than the heating plate group (Δ<em>T</em><sub>skin</sub> = 4.86 ± 1.21 °C vs. 1.72 ± 0.70 °C, respectively), suggesting that handling may amplify heat gain. Warmer salamanders were more prone to be active regardless of whether they were handled or in contact with a heating plate. Our results demonstrate that short-term handling can cause rapid warming that exceeds rates used in heat stress studies, with implications for data reliability and amphibian welfare in thermal biology assays.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"136 ","pages":"Article 104390"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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