1) Run at a slower pace.
2) Drink plenty of fluids that contain electrolytes(don’t forget to drink before running). Sports drinks are better than water in very hot weather. Make sure you are getting enough sodium and magnesium in particular.
3) Unless you are very used to running in the heat, take short breaks every 20 minutes both to cool off and to replace fluids.
4) Wear light colored clothing since these keep you cooler than dark colored clothing. Consider running bare-chested(guys only).
5) Apply sunscreen liberally. Not only to prevent sunburn and skin cancer, but because sun-damaged skin doesn’t sweat and cool off as efficiently.
6) If you’re new to running in very hot weather, give yourself a week to acclimate yourself. Don’t over do it. Your sweat glands need time to adjust.
7) Unless you’re a pro, don’t push yourself or try to set new records except on cooler days.
8) Joggling will make you sweat more than just running, so you may need even more water and electrolytes compared to regular runners if you joggle.
9) If it is dangerously hot, and humid, and there’s an ozone alert(which means poor air quality), consider running on a treadmill indoors.
10) If you believe you are experiencing heat exhaustion, stop exercising immediately and seek shelter in a cool place as soon as possible. Drink plenty of electrolyte-containing fluids if also dehydrated.
11) Avoid outdoor exercise during the time of day when the temperature is at its hottest.