Exploring how the human body responds to extreme heat as a result of climate change

None listed

Climatologists currently estimate that the environmental threshold for human heat tolerance is 6 hours at a wet-bulb temperature (Twet) of 35 °C. When accounting for human physiological thermoregulatory variables such as metabolic heat production and sweating capacity, however, it is likely that this threshold is severely underestimated. Contrary to the assumptions made by the 35 °C Twet model, in real-world scenarios, people expend anywhere between 1.5 to 5.0 METs to perform activities of daily living, and the ability to cool down through sweating is limited in certain conditions. Specifically, in very humid environments, evaporative capacity is limited by a low vapour pressure gradient between the air and skin; whereas in very dry environments, it is limited by the ability of the body to produce sweat. This is an important distinction because the same Twet can be represented by different combinations of air temperature and relative humidity, which means that the limiting factor to achieving heat balance will be different depending on the environmental conditions being experienced. It is more than likely that the limits to human heat tolerance are not represented by a universal Twet temperature threshold, but rather differ based on the type of heat stress an individual is exposed to (i.e., humid vs. dry). This theory has only ever been modelled and has never been tested in human subjects which is imperative to moving this area of research forward.

No related papers found yet.