The summer solstice has only just arrived, but there's no mistaking the season: A heat wave has been smothering swaths of the Northeast and Midwest this week, with temperatures smashing records in cities throughout New England and Maine. Though these spots will get some relief this weekend, the National Weather Service forecasts continued highs in the 90s and above across the Ohio Valley to the Mid-Atlantic—and of course, months of summer stretch ahead for us all. So there's no time like the present to brush up on the best way to rehydrate yourself when you're quite literally baking.

While there's no magic number of glasses of water we should all drink in a day (given we're different sizes and have varying diets and levels of physical activity), one thing is certain: "We need to drink more water when we spend time in hot environments, which cause us to lose water [in our bodies] through sweating," Riana Pryor, PhD, ATC, the director of the Hydration, Exercise, and Thermoregulation (HEAT) Laboratory in the Center of Research and Education in Special Environments at the University of Buffalo in New York, tells SELF.

That means learning the best way to rehydrate your body in the heat is key to having a cool (not cruel) summer.

First, let's discuss why it's crucial to stay hydrated in high temperatures.

Like many good things in life, hot weather is best in moderation. I adore a beach day as much as the next person, but the truth remains that too much exposure to heat raises your risk for heat illnesses, like heat cramps, heat exhaustion, and heat stroke, "which happen when someone's core body temperature rises due to being in a hot environment and many times are associated with fatigue from physical activity in the heat," Dr. Pryor says.