Our maximum heat tolerance depends on humidity, but climate change is threatening our health which is affected by high temperatures
Climate change is causing temperatures to rise around the world, but extreme heat is a threat to the health of living things. The human body can only take the mugginess so far. A 2020 study published in the journal Science Advances indicated that the maximum temperature a human can tolerate is of the wet bulb of 95 degrees Fahrenheit, or 35 degrees Celsius. The wet bulb temperature, however, does not match the air temperature reported by meteorologists. Everything basically depends on humidity.
Wet bulb temperature and how hot we can take it
Wet bulb temperature is measured by a thermometer covered with a water-soaked cloth and takes into account both heat and humidity. The more water there is in the air, the harder it is for sweat to evaporate from the body and cool a person. According to Colin Raymond, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory, if the humidity is low but the temperature is high, or vice versa, the wet bulb temperature probably won’t approach the critical point for the human body. On the other hand, when both humidity and temperature are very high, the wet bulb temperature can reach dangerous levels. For example, when the air temperature is 46.1°C and the relative humidity is 30%, the wet bulb temperature is only about 30.5°C. But when the air temperature is 38.9°C and the relative humidity is 77%, the wet bulb temperature is about 35°C, which is the maximum that can be endured.
The reason why people cannot survive high temperatures is related to the fact that in these cases they can no longer regulate their internal temperature. “If the gradation of the wet bulb exceeds that of the human body, you can still sweat, but you won’t be able to cool your body to the temperature it needs to function physiologically,” Raymond told WordsSideKick.com. At this point, the body becomes hyperthermic and according to the National Institutes of Health you may experience symptoms such as increased heart rates, lack of sweating, loss of senses to coma.
Raymond however pointed out that a wet bulb temperature of 35°C will not cause immediate death because it will take about 3 hours before the heat becomes unbearable. In reality, these are estimated temperatures that depend on several factors and even lower gradations can be deadly. For example, people who are elderly or have certain health conditions, such as obesity, because they are unable to regulate their temperature, may not survive even in less than 35°C of wet bulb.
Currently, some locations have already experienced extreme heat conditions for one or two hours that can be detrimental to survival and it is predicted that in the next 30-50 years, with global warming, areas of northwestern Mexico, northern India, southeast Asia and West Africa will be at risk. Climate change is threatening numerous species of living things and, another study, estimated that we have only 10 years left to save coral reefs.
Stefania Bernardini