It's that time of year for most of the country. Hot and sometime very hot days. Still, you want to go for a run without risking heat exhaustion. I have some suggestions.
1) Time-if at all possible, run just after sunrise or just before sunset. If its more than 90 degrees, don't run between 9am and 4 pm.
2)Before run-hydrate, drink water, gatorade or other fluids, except coffee or tea (which will dehydrate you) as much as you can drink without feeling bloated. Sunscreen is very important. I suggest using a "sport" sunscreen that doesn't wash off with sweat or water.
3)During run-if the run is more than an hour, take fluids with you. Either in a carry bottle or a camelback type pack.
4)Types of runs. Trails are better than running on the street in most cases. Trails will offer shade either part of the run or larger parts of the runs. The mix of sun and shade is much safer than running on asphalt or concrete where the sun reflects and absorbs the heat. If you have to run on the streets, try to run a route that has more shade coming back because by that time in your run, you'll be dehydrated. You don't want to run your last half of your run in the blinding sun with no fluids.
5)Post-run. Hydrate right away. Gatorade or something like that works best. Get out of the sun and preferrably near some air conditioning. Stay out of the sun the rest of the day. It's not the time to sit outside in the sun. Wait until sunset before going outside.