When the heat is on: Drink up, cool off and chill out

By Sam Fellin, D.O., internal medicine, Providence Medical Group-Scholls

Here in the Pacific Northwest, we treasure every minute of summer sun. It's understandable that we're sometimes tempted to run that extra mile or put in a marathon workday in the yard, even when the temperature hits the high notes. But there's nothing like a case of heat exhaustion to tell you that you've overdone it.

Heat exhaustion can hit you hard and fast if you're not drinking enough water to keep your body's cooling system running. Your body cools itself by sweating, and you need to keep your fluid levels topped off to replace what you sweat out. You lose a lot of fluids when you're active, even in fairly low heat. In higher temperatures – especially in dry environments – you can lose moisture just by breathing.

When you fall behind in replacing lost fluids, your body can no longer sweat enough to keep itself cool. Before you know it, you're feeling awful, with any or all of the classic symptoms of heat exhaustion:

  • Profuse sweating
  • Nausea
  • Headache
  • Dizziness
  • Weakness or fatigue
  • Pale, cool, moist skin
  • Muscle cramps
  • Extreme thirst

If you start feeling these symptoms and don't do anything about them, heat exhaustion can progress to heat stroke, a much more serious problem in which the body loses all ability to cool itself. Heat stroke is a medical emergency – but it never has to get that far. You can prevent heat exhaustion entirely by paying a little more attention to the heat and your hydration. Here's how:

Don't wait until you're thirsty – drink up: If you wait to drink until you feel thirsty, you're already 10 to 15 percent dehydrated and you'll have to drink even more to catch up. Stay ahead of your thirst by drinking lots of water, whether or not you feel thirsty. Carry a water bottle with you when you're working or playing outside to remind you to drink a lot. The hotter it gets, the more water you should drink.

Avoid alcohol and caffeine: Having a few beers may make you feel as though you're replacing fluids, but it's actually making the situation worse. Alcohol dries you out and makes you less sensitive to heat. Coffee, tea, sodas, energy drinks and other caffeinated drinks can increase fluid loss as well. The best choice is water.

Work a little, rest a little: In hot weather, don't spend hours at a stretch working out in the sun. Take frequent breaks to rest in the shade, cool down and drink fluids. The hotter the heat, the more frequent – and longer – the breaks should be. In the 90s? Take a 15-minute break every 15 or 20 minutes. Triple digits? Maybe you really shouldn't be out there. Find a hammock in the shade or a cooler way to exercise.

Pay attention in the bathroom: When you're well-hydrated, you should feel the need to urinate fairly often, and your urine should be clear. If you go several hours without feeling like you have to go, and you only produce a small amount of dark urine, you're not drinking enough water.

Check the heat index: The National Weather Service daily heat index combines temperature and humidity to give you an overall prediction of heat danger. Be sure to check it on hot days and plan your activity accordingly. Also remember to check it when you're traveling – other areas of the country may have a lot more humidity than you're used to, which can put you at risk.

Know your own risks: Many things can influence your body's ability to regulate heat, including:

  • Medications such as ace inhibitors and beta blockers
  • Age: Older adults and younger children don't thermo-regulate as well
  • Excess weight, which makes it harder for the body to dissipate heat
  • Chronic conditions such as diabetes, heart failure and cancer

What to do in case of heat exhaustion or heat stroke

If you feel the signs of heat exhaustion, stop what you're doing, rest in a cool, shaded area, and drink lots of fluids (water and/or electrolyte-replacement drinks). If you're really hot, cool yourself with a cloth dipped in cool water or get into a cool bath. If your symptoms feel moderate to severe, keep up the fluids and be alert for signs of heat stroke, which may include any of the following:

  • Hot, red, dry skin
  • No longer sweating
  • Confusion
  • Cramps or vomiting
  • Loss of consciousness

While home treatment is fine for heat exhaustion, heat stroke requires emergency medical treatment. If someone you are with shows signs of heat stroke, call 911 immediately. While waiting for help to arrive, remove as much clothing as possible from the person, wet him down with cool water and fan him to dissipate heat, since by then he may not be able to swallow fluids.

A little awareness goes a long way

By all means, enjoy every day of our all-too-short summer, but be aware of what you're doing and what the temperature – or heat index – is going to be. And remember the three keys to preventing heat exhaustion: Drink, drink and drink more water.


Get more information on heat exhaustion and other heat-related illnesses in our health library.