Maybe I am lucky to have airconditioning, but I do all my exercise indoors when it gets hot. I admit I get cabin fever and feel restless that I can't go out to walk, but, hey, I would rather not get sick! I know folks who ride or run or walk early in the morning but lately it stays hots all night! They all drink a LOT more water and have a wet towel to put around their necks to cool off. Be careful out there - but if you can, stay in the cool. Maybe a mall is a good place to walk on hot days?