I'm guessing you guys wouldn't experience all that much humidity down there in SA, more dry outback air? We've had a few hot ones up here. I can live with a few 45C days fine (113F for our American friends) - it's mainly the humidity factor on even the (relatively) cooler days that makes things a little unpleasant for some people at times up here (all the moist equatorial air moving down the coast).
We get the odd days of 60%+ humidity and that wipes out everyone!
I lived up on the North coast of NSW for about 3 months of Summer back in 2005 and the humidity doesn't really wipe me out like it may others. That was the subtropics though, I gather you are up in the tropics?