Wet bulb thermometer is the kind that a pair of thermometers are mounted together with one wrapped in wet cotton and the other dry. Typically between the two glass tubes is a little look up table that gives humidity from current dry bulb temperature and delta between the two.

I don't know what exactly environment reaching 35C/95F web bulb means, but considering 1) it indicates temperature of a thermometer cooled by evaporation, and 2) body temperature of a human is ~40C/100F, I think it means evaporative cooling aka sweating is becoming useless. It won't be a huge stretch to consider that unsurvivable.

Wet bulb 35C is equivalent to a heat index of 160F.

One issue that people who haven't experienced extreme heat might not realize is a lot of people just pass out really quickly. While it takes a while to go past the point of no return and they theoretically could be egressed to somewhere they can cool off and recover, if they're alone, they're not going to.

I understand you are probably American and therefore not used to Celsius but just so you know the body of a human is around 37.7 °C. 40 °C is already life-threatening.

"I think it means evaporative cooling aka sweating is becoming useless. It won't be a huge stretch to consider that unsurvivable."

This assumes there are no alternatives to evaporative cooling via sweat.

Indeed. Strapping on a pair of active CPU heatsink through a B6 sized aluminum cold plate to the back of waist helps immensely in that kind of climate. But it needs constant 12V/0.5-1A DC supply.

What are you even talking about?

My legitimate comments get downvoted and crap like this does not...

That’s what I do when humidity is unbearable but air temperature is below body surface. Works ok.

Yet people did. The heat stroke at 35C° wet bulb if far from instantaneous.