Some of it is acclimation. You do learn to tolerate the heat better. I am always drenched in sweat the first really hot days of the summer which gets better. But high heat which approaches the wet bulb temperature is just stressful on the body. Subject a person with moderate heart failure or kidney problems to such conditions and they may do badly. In normally very hot climates, the health burden of that is spread out over time, year after year, not bunched up all at once.

> But high heat which approaches the wet bulb temperature is just stressful on the body.

Note that "wet-bulb temperature" (WBT) is not a specific value for temperature, it is a way of measuring temperature. You can cave a WBT of 0C, or a WBT of 35C. WBT is the temperature shown by a thermometer covered in a wet cloth over which air is passing.

This is relevant because it indicates the temperature that human skin can reach with any amount of sweat and wind. It is normally much lower than air temperature because of evaporative cooling effects; but, as humidity increases, WBT and air temperature get closer and closer; at 100% humidity, there is no more evaporation, so WBT becomes equal to air temperature.

The problems for human activity start at a WBT of 32C (90F), and a WBT of 35C (95F) means that even healthy humans with access to unlimited water will die of heat stroke in the shade after a few hours.

Thank you for the explanation, I learnt something.

> The problems for human activity start at a WBT of 32C (90F), and a WBT of 35C (95F) means that even healthy humans with access to unlimited water will die of heat stroke in the shade after a few hours.

It’s incredible to think how “fragile” we can be. 35C is not cold or cool but it’s not extreme either. When you think about it, if your core temp drops to 35C you have (severe?) hypothermia. But if your skin can’t get cooler than that you die of heatstroke. Crazy to think about. Even crazier that we terraformed our planet to make this a reality in many more places than we started with.

I've been in a room with a wet bulb temp of 115 F. You walk in, water condenses on you and your clothes.

The max time you can be in that environment is one to two hours.

Is it really normal to have temperatures in the 35-49 range there? I can’t even imagine

Argentina gets easily 30+ in the summer, 40+ is not unusual

Co-worker from Mumbai (yeah, here-say, I know) mentioned temperature up to 50C in the summer.

Mumbai is horrific because of the humidity on top of the high temperature. I’ve been there a couple of times, though never during a heat wave. I would not want to live there.

Depends where you were in BC.

Victoria was >15 degrees colder than Kamloops for instance.

You have 50°C in South America?