I can tell you from experience, when it's 115C in the shade and over
50% humidity you don't go out without your shirt on - particularly in the sun. I found a light cotton T shirt was "comfortable" but not as good as a light loose fitting cotton shirt. that let the air move. You stayed in the shade as much as possible, and tried to find a spot with a breeze. With high humidity sweating didn't help - and the only way you got any evaporation was with a breeze. That late October 1973 afternoon at 115 in the shade was a "cool comfortable" day compared to the 2 weeks before. (when the RH was occaisionally actually over 100% - and yes, that IS possible!!!) The humidity is highly localized close to the falls -a HUGE humidifier. The rains come in November