Compared to other organisms, human survival is subject to strict environmental constraints. That is to say, our species is very fragile in the face of climatic ups and downs.
However, answering the question of what is the maximum temperature a person can withstand is not so simple. The response depends on multiple factors such as air quality, physical condition, clothing and even race. One of the most important variables is, undoubtedly, environmental humidity.
The body temperature of a healthy human being is around 37º C. When thermometers rise, perspiration maintains this variable stable. Yet, the cooling mechanism only works when sweat evaporates. This physical phenomenon only occurs if environmental humidity is low.
According to examples taken from an interesting infographic published on Live Science, the environmental conditions under which one may suffer from hyperthermia after being outdoors for an hour are the following:
- About 45-46º C with around 50 % relative humidity.
- About 35º C with 100 % humidity.
Although it may seem otherwise, these values are not so difficult to reach and are no longer exclusive to tropical areas. In Canada’s last heatwave, temperatures reached 32º C in cities like Vancouver with approximately 70 % humidity (similar to cities like Barcelona), resulting in an apparent temperature of about 40º C. Climate change? Yes, it could be a factor.