- Avoid running during the worst heat. Early in the morning is best, and late evening trumps a lunch time run. Temperatures may not be quite as high, and it will be easier to find shade to run in since the sun will not be as high in the sky.
- Avoid running with traffic. Your body absorbs up to 8 times more oxygen and pollutants when you breath through your mouth instead of your nose. Try to avoid running with traffic and definately do not run with rush hour traffic. Your lungs will thank you.
- Drink plenty of water before your run. This should go without saying, but being hydrated before you begin your workout is important. You will have more energy to do the work itself, and your body will not have to work quite as hard to cool itself down.
- Drink plenty of water during your run. If you can manage it, drink plenty of water while you are working out. The ultimate goal is to weigh the same after your run as you did before your run, but this is especially difficult on hot days. If you have extra water you can dump some over your head or shoulders, but be sure that you have had plenty to drink first. Your body will cool off better if you consume the water instead of splashing yourself with it.
- Slow down. In extreme heat, you will require more effort for a slower pace. Don’t try to push it, and if you start to feel dizzy or nauseous then you should immiediately slow down or even stop.
- Wear sunscreen. If it is sunny out, wear some sunscreen that will stay on through your sweat. It will help prevent your skin from getting burned (which will decrease the likelihood of getting cancer later in life) and can help provide another layer between your skin and the hot air. It won’t keep you cool on its own, but every little bit helps.
- Wear technical fabrics. Cotton and sweat are a bad combination; wear technical fabrics such as gore-tex that will wick the sweat away from your body. Cotton absorbs the sweat which will then provide an extra layer of insulation that you do not need. Technical fabrics wil help keep you cool, and will help prevent chafing and blisters.
This is by no means an exhaustive list, but it is a quick list of the easiest steps to keeping cool if you are going to run in the heat.