Too many, in fact, because most of them could have been avoided in the first place. Headaches come in several varieties, but the most common types are tension and migraine. A few simple strategies can help you steer clear of either. Drink lots of liquids, especially when it's hot.
Dehydration can bring on headaches.
Get regular, moderate exercise. Don't overdo it though. Going too hard or trying to lift heavy weights can bring on an exertion headache. Try not to skip meals. Headaches are more likely when your blood sugar drops because of lack of fuel.