Please be extremely careful about heatstroke. If you are already experiencing headaches or nausea, you may be at a moderate stage of heatstroke. Using a parasol, drinking plenty of water, and getting enough sleep are effective ways to prevent it. By the time you feel thirsty, your body is already dehydrated. It’s important to drink water frequently, even before you feel thirsty. More trips to the bathroom? That’s a good thing. Passing pale-colored urine actually helps prevent kidney stones.