Human thermoregulation: separating thermal and nonthermal effects on the body's capacity to dissipate heat

长时间暴露在炎热的环境/过程和/或进行剧烈运动可以使身体变热，导致体内温度显著升高。为了抵消这种增加，激活了强大且高度发达的行为和自主热调节反应，以增强全身热损失。除了热损失反应的热控制外，越来越多的证据表明，非热因素[与身体感觉受体（如压力感受器、代谢受体等）的激活有关的因素以及个人因素（如衰老、适应环境等）]可以对身体在热应激期间的散热能力产生深远的影响。我的NSERC研究计划旨在了解这些因素在热应激期间的单独和综合贡献。我正在研究人体热损失反应的非热调制机制，使用我的世界上唯一的全身热量计（一种测量身体散发热量的装置）来测量身体散热能力的变化。我工作的一个重要组成部分是整合其他生理系统（心血管、代谢等）反应的同步测量能力。这使我对人类体温调节的热和非热控制器之间复杂的相互作用有了前所未有的了解。作为这笔拨款的一部分获得的资金将用于更换和升级我的热量计中独特集成的关键仪器。这包括1)用于评估皮肤血流的激光多普勒血流测量装置，2)用于测量多种血流动力学参数的非侵入性血流动力学系统，以及3)用于测量氧气消耗和二氧化碳产生的气体分析仪（用于量化和/或调节产热率）。我的研究结果将有助于开发管理工具来控制或消除热应激条件，并在热应激条件下保护个人的健康和安全。它还可以用来刺激技术/解决方案的发展，以提高工业流程效率（通风系统，新服装设计，个人冷却系统等）。

Prolonged exposure to hot environments/processes and/or performing strenuous exercise can heat the body causing significant increases in internal body temperature. To offset this increase powerful and highly developed behavioral and autonomic thermoregulatory responses are activated to enhance whole-body heat loss. Independent of thermal control of heat loss responses, there is increasing evidence demonstrating that nonthermal factors [those associated with the activation of the body's sensory receptors (i.e., baroreceptors, metaboreceptors, etc.) as well as personal factors (i.e., aging, acclimation, etc.)] can have profound consequences on the body's ability to dissipate heat during heat stress. My NSERC study program is directed at understanding the separate and combined contribution of these factors during heat stress. I am studying the mechanisms underlying the nonthermal modulation of the body's heat loss response using my world's only whole-body calorimeter (a device for measuring the heat emitted by the body) to measure changes in the body's capacity to dissipate heat. A critical component of my work is the ability to integrate the simultaneous measurement of responses of other physiological systems (cardiovascular, metabolic, etc.). This has enabled me to achieve an unprecedented insight into the complex interplay between thermal and nonthermal controllers of human thermoregulation. Funds obtained as part of this grant will be used to replace and upgrade critical instruments uniquely integrated for use in my calorimeter. This includes 1) a laser-Doppler flowmetry unit for assessing skin blood flow, 2) a non-invasive hemodynamic system to measure multi-hemodynamic parameters, and 3) gas analyzers for measuring oxygen consumption and carbon dioxide production (used to quantify and/or regulate rate of heat production). My study findings will help in developing management tools to control or eliminate heat stress conditions and protect the health and safety of individuals during heat-stress conditions. It can also be used to stimulate the development of technologies/solutions to improve industry process efficiencies (ventilation systems, new clothing designs, personal cooling systems, etc.).