验证人类温度调节的新极限
Robert D Meade1,2, Fergus K O'Connor1, Brodie J Richards1
1Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
概括
新的研究验证了用于评估在极端高温下人类生存能力极限的热度步骤协议. 这些研究确定了温度调节的临界湿球温度值,这对于了解热应激风险至关重要.
科学领域:
- 环境生理学环境生理学
- 人类温度调节
- 适应气候变化 适应气候变化
背景情况:
- 全球预测显示,越来越多的热量和湿度超过了人类温度调节的极限.
- 以前的生存极限是基于实验室研究,理论上值为35°C湿球温度 (Twb).
- 较新的经验极限使用来自热阶段协议的核心温度拐点,但它们的有效性尚未确立.
研究的目的:
- 验证使用湿度步骤协议来确定核心温度屈曲的Twb值.
- 为了评估这个值是否准确地划分了Twb,在这个Twb以上,人类的温度调节变得不可能.
- 评估热阶段协议的可靠性,以评估暴露在热中的生存极限.
主要方法:
- 采用湿度步骤协议,估计了12名志愿者的核心温度屈曲的Twb值.
- 参与者随后暴露在Twb以上 (~33.7°C) 和以下 (~30.9°C) 他们的个体拐点 (~32.3°C) 长达9小时.
- 持续监测核心体温的变化,以评估温度调节能力和预测热中风的发生.
主要成果:
- 当暴露在曲点以上的Twb (Tabove) 时,核心体温持续增加.
- 在Tabove条件下,预计热中风 (40.2°C核心温度) 会在10小时内发生.
- 虽然Tbelow也无法弥补,但核心温度上升的速度明显较低,预计热中风在24小时内开始.
结论:
- 该研究验证了热阶段协议作为评估热暴露生存限值的有效方法.
- 这些发现提供了对Twb值的直接评估,超出这个值,人类的温度调节是不可持续的.
- 这项研究完善了我们对关键热应激值的理解,对公共卫生和气候适应战略产生影响.
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