[barry-cotter]

It happens to you too if you live there long enough. Likewise if you spend a lot of time outside in the cold you too can walk around in shorts and sandals in freezing temperatures with no ill effects (as long as it’s dry with low winds)

[rocknor]

I wish more people understood this. No, 35°C is not "too hot", 90% RH is not "too humid" and 10°C is not "too cold", your body is just not adapted to it yet like the locals.

[tharkun__]

35C or over is not too hot, if it's dry enough that the body can regulate its own body temperature.

Even 100% RH is not a problem if it's cold enough.

10C is definitely not too cold and much much colder temps are totally fine if you are bundled up.

The problem apparently becomes high relative humidity paired with temperatures that are too high for the human body to cool itself. We all know what happens if you get a fever that's too high (i.e. body temp goes way up): you die!

    Wet-bulb temperature is a measure of heat and humidity that expresses how human bodies will experience the temperature. It is so named because it is calculated by wrapping the bulb of a thermometer in a wet cloth. In low humidity, water will evaporate from the cloth, carrying away heat and cooling the thermometer in the same way sweat cools the human body. In these conditions, the wet-bulb temperature will be lower than the air temperature. In high humidity — when the air is more saturated with water vapor — the water cannot evaporate as easily so the cloth stays hot. If the wet cloth cannot cool below the air temperature, neither can human skin.

Humans being humans, we invented stuff to help us both be more comfortable because many of these conditions are still uncomfortable, even if they don't kill you and to not die even if the conditions are made for it (easiest example being: it's -40C outside, yes without bundling up a lot you will also be able to die from this.

I.e. in dry climates, have passive evaporative coolers (if you have enough water supply), preferably in houses that have good airflow and are painted white instead of having black tar roofing (think the old white houses built in spain for example).

The modern humans use AC in most places now. Which does come with its own problems.