The Wet-Bulb Peril Has Arrived… Way Too Early 

The human body has limits. If “temperature plus humidity” is high enough, even a healthy person seated in the shade with plentiful water to drink will suffer severely or likely die. It’s the Wet-Bulb Temperature WBT effect. There is an upper limit to human capacity to adapt to excessive global heat when combined with excessive More

Source: The Wet-Bulb Peril Has Arrived… Way Too Early – CounterPunch.org