At a wet-bulb temperature of 95F (35C), thermal stress is lethal to humans in a few hours in most cases.
While air temperatures routinely exceed 95F (which is already hot), that's generally at much lower humidities. A wet-bulb 95F means that relative humdity is 100%, and the body effectively cannot cool itself.
Even swimmers have been known (or suspected) to succumb to thermal stress when swimming through warm waters. The international body governing open-water competitions has set an upper bound for competitions of 31C (87.8F):
http://www.swimmingworldmagazine.com/lane9/news/Commentary/3...
Most swimming pools are heated to between 78 and 82F. The difference between the lower and upper ends of that range are pronounced: slightly cool to slightly warm if you're not very active. Many swimmers will find anything over 80F unpleasantly warm, and may prefer cooler temperatures, though lower than about 72F generally feels chilly regardless.
While air temperatures routinely exceed 95F (which is already hot), that's generally at much lower humidities. A wet-bulb 95F means that relative humdity is 100%, and the body effectively cannot cool itself.
You're also going to have trouble cooling yourself from your surroundings, as everything will be that warm -- water, ground, etc. http://www.tgdaily.com/sustainability-features/49635-future-...
Even swimmers have been known (or suspected) to succumb to thermal stress when swimming through warm waters. The international body governing open-water competitions has set an upper bound for competitions of 31C (87.8F): http://www.swimmingworldmagazine.com/lane9/news/Commentary/3...
Most swimming pools are heated to between 78 and 82F. The difference between the lower and upper ends of that range are pronounced: slightly cool to slightly warm if you're not very active. Many swimmers will find anything over 80F unpleasantly warm, and may prefer cooler temperatures, though lower than about 72F generally feels chilly regardless.