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

人体体温调节：区分对身体散热能力的热效应和非热效应

• 批准号: RGPIN-2014-06313
• 负责人: Kenny, Glen
• 金额: $ 6.56万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=630924
• 关键词: Human; thermoregulation; separating; thermal; nonthermal

Temperature regulation is a vital aspect of human survival as relatively small deviations in internal body temperature can lead to profound disruptions in whole-body heat balance. 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. Inherent to this response is the concept of set-point about which internal body temperature is regulated. The body’s temperature regulatory center is located in the hypothalamus of the central nervous system. Input to this center comes from temperature sensitive receptors in both the skin and the internal core regions of the body. Changes in skin and/or core temperature initiates a series of physiological actions aimed at enhancing heat dissipation. This heat is lost by contact with cool air and by sweat production, which cools your body as the sweat evaporates. However, when the body is unable to cool itself by sweating, several heat-induced illnesses such as heat stress or heat exhaustion and the more severe heat stroke can occur, and can result in death. Independent of thermal control (i.e., by changes in skin and/or core temperatures) of heat loss responses, there is increasing evidence demonstrating that nonthermal factors can have profound consequences on the body’s ability to dissipate heat during heat stress. These nonthermal factors include those associated with the activation of the body’s sensory receptors (i.e., baroreceptors, metaboreceptors, mechanoreceptors, etc.) as well as personal factors such as sex, aging, acclimation, etc. However, little is known about the mechanism underlying the nonthermal influence on human heat dissipation. My proposed study program is directed at understanding the separate and combined contribution of these factors during thermal challenges to human heat balance associated with elevations in environmental and metabolic (exercise) heat load. To achieve an advanced understanding of the role that nonthermal factors may play, we will study the mechanisms underlying the nonthermal modulation of the body’s heat loss response from both a local and whole-body perspective. We will use the world’s only whole-body calorimeter (a device for measuring heat emitted by the body) to precisely measure changes in the body's capacity to dissipate heat as function of these different factors. Moreover, in order to acquire a better understanding of the integration and coordination (interplay) of the human response to heat stress, the evaluation of thermoregulatory function will also be paralleled by the simultaneous measures of different physiological systems. By understanding the precise combination of environmental and metabolic heat loads where physiological differences in the body’s capacity to dissipate heat occur in relation to these nonthermal factors, we can begin to develop a better understanding of how heat stress develops. Such information will have important practical benefits for many sectors of our society including the military, industry, sporting organizations and the general public. By understanding the interplay between thermal and nonthermal controllers on human thermoregulation, we can develop/improve management tools to control or eliminate heat stress conditions and protect the health and safety of individuals/workers during heat-stress conditions. Moreover, this knowledge can be used to stimulate the development of new technologies and solutions that will improve industry process efficiencies (e.g. ventilation and refrigeration, spot cooling techniques, new clothing designs, etc.).

温度调节是人体内部温度的偏差n偏差的重要方面内部温度是定期的调节中心的固定点位于中央神经系统中。在生理动作方面，人们无法通过出汗来加剧散热，几种热诱导的疾病（例如热应激或热量呼气和troke）可能会出现热量损失反应，这是越来越多的证据表明非热因素可能会产生深远的后果，以散发热应力。在机制上，很少知道对人类热量的校正，并在环境中的热量（锻炼）高度升级。此外，人体的热量反应仅来自全身量热计的功能，以便更好地了解整合和辅导（人类对热应激的相互作用通过与这些非热因素相关的人体散发热量的生理差异，通过环境和代谢热量的精确组合进行了不同的措施。在人类热调节中，在热量调节的热控制器和非热控制器之间，军事，体育组织和公众都可以开发/改善管理工具，以保护或d保护新nt期间个人/工人的健康和安全性提高行业流程效率的技术和解决方案（例如通风和冰镇，斑点冷却技术，NE W服装设计等）。