Integrated physiological adaptations to heat acclimation in humans

热暴露是对人体的一种挑战。然而，当人体反复暴露在高温下时，它是有适应能力的。这个过程被称为热习服，可以让身体更好地控制内部温度。广泛的研究已经描述了人类热适应的迹象，但伴随这些迹象的生理变化仍然知之甚少。这项研究计划的目标是确定和更好地了解伴随着人类热适应的生理变化。为了实现这一目标，将进行研究，以解决5个目标。第一个目标是确定提供最佳适应的热适应方法。第二个目标是检查中枢(神经系统)和外周(汗腺、皮肤血管)变化对更好地控制体内体温的相对贡献。第三个目标是检测血液容量和热休克蛋白作为导致热习服的潜在生理机制。第四个目标是在与体内体温控制没有直接关系的系统中检查热适应后的适应性。具体地说，将研究心血管系统和自主神经系统的变化。第五个目标将决定年龄如何影响身体适应高温的能力。这一研究项目的结果将进一步加深我们对人体适应热暴露能力的理解。这一知识可导致制定更好的战略，旨在改善加拿大人在工业和/或军事环境中的工作，他们必须在炎热的环境条件下履行职责。这种策略尤其必要，因为加拿大工人已经在忍受高于平均水平的环境温度，预计他们在不久的将来将暴露在更频繁、更强烈和更持续的极端高温事件中。

Heat exposure represents a challenge to the human body. However, the human body has the ability to adapt when it is repeatedly exposed to the heat. This process, termed heat acclimation, allows the body to better control its internal temperature. Extensive research has described the signs of heat acclimation in humans, yet the physiological changes which accompany these signs remain poorly understood. The goal of this research program is to determine and better understand the physiological changes that accompany heat acclimation in humans. To achieve this goal, studies will be performed to address 5 objectives. The first objective is to identify the method of heat acclimation that provides optimal adaptations. The second objective is to examine the relative contribution of central (nervous system) and peripheral (sweat glands, skin blood vessels) changes that lead to a better control of internal body temperature. The third objective is to examine blood volume and heat shock proteins as potential physiological mechanisms which lead to heat acclimation. The fourth objective is to examine adaptations following heat acclimation in systems that are not directly related to the control of internal body temperature. Specifically, changes within the cardiovascular and autonomic systems will be studied. The fifth objective will determine how age affects the ability of the body to acclimate to the heat. The results from this research program will further our understanding regarding the ability of the human body to adapt to heat exposure. This knowledge could lead to better strategies aimed at improving the work of Canadians in industrial and/or military settings who must perform their duties despite hot environmental conditions. Such strategies are particularly needed, as Canadian workers are already enduring above-average ambient temperatures and they are expected to be exposed to a greater frequency, intensity and duration of extreme heat events in the near future.