For many of us, summer means lots of time spent outside, soaking up the glorious sunshine. You probably already know to slather on sunscreen and fill up that water bottle before you head out the door.
Alison Ozgur, MAT, MHS, RDN, DipACLM
But what about when the heat is particularly intense or you’re planning to be outside longer than usual?
The standard advice might not be enough to keep you safe when you’re working, exercising, or vacationing in soaring temps.
With heat waves becoming more common, we turned to Alison Ozgur, a registered dietitian nutritionist (RDN) who supports student well-being at one of the biggest universities in the country. This longtime Arizona resident knows a thing or two about serious summer heat, so check out her advice for staying cool and hydrated as the mercury rises.
How Heat Affects the Body
This may surprise you: More people die from extreme heat than any other weather event. Heat becomes particularly dangerous when outside temperatures top 90 degrees Fahrenheit and the humidity is over 50 percent. Those conditions combined can make the outdoors seem even hotter, sometimes described as the “heat index” or the “feels like” temperature.
“The health effects of heat take a while to kick in, so it can sneak up on you,” Alison explains. “Plus, I think people tend to misjudge their ability to manage hot weather.”
Heat puts stress on the body in several ways:
- You lose fluid through sweat. Your body naturally cools itself through sweating, but too much can dehydrate you. Once you fall behind on fluids it can be hard to catch up.
- You also lose important minerals (namely sodium, chloride, and potassium) through sweat. These substances, called electrolytes, support important body processes like fluid balance, muscle function, and heart function.
- Your heart must work harder as your blood volume decreases, which happens as you get dehydrated in high heat, and can contribute to a faster heart rate and lower blood pressure.
- You can’t self-regulate body temperature as well. In extremely hot and humid weather, your skin doesn’t release as much heat and sweating becomes less effective at cooling you off. Significant health problems can begin when your internal temperature reaches 101 degrees or higher.
The longer a heat wave lasts, the higher the risks. In the short term, you can develop illnesses like heat exhaustion or heat stroke, which can be life-threatening. In the long term, prolonged dehydration can lead to kidney stones, urinary tract infections, and other health issues..
Tips to Protect Yourself in a Heat Wave
Clearly, serious heat is serious business, but Alison assures us there is a bright spot. “You can’t outsmart the heat, and you can’t always hydrate your way out of it,” she explains. “But you can absolutely take steps to prevent its effects.”
Here are her top recommendations.
1. Tune in to the Forecast
Use weather apps and sign up for local weather alerts. Knowing when a heat wave is coming will help you plan ahead.
2. Sip Early and Often
Hydration remains crucial in a heat wave. Alison recommends a glass of water first thing in the morning to counteract dehydration from those eight hours without fluids. Drink more before you head outside and consistently throughout the day.
How much water should you drink? An easy calculation is to consume half your body weight in ounces—so if you weigh 150 pounds, aim for at least 75 ounces each day. This goal goes up if you’re very physically active and under extreme heat conditions.
Don’t wait until you’re thirsty to drink, Alison warns, because by then you’re already dehydrated. “You want to get a jumpstart and catch dehydration before it happens. That makes a big difference,” she says.
Frequent, small amounts of fluid are better than large amounts, especially in the heat. The Centers for Disease Control and Prevention recommend drinking 1 cup (8 ounces) every 15 to 20 minutes when you’re working in the heat. If you have trouble remembering, set an alarm or use a water bottle with motivational markers printed on the side.
Plain water is hard to beat. But if you crave more variety, here are some flavorful ideas:
- Dress up your H2O with berries, lemon wedges, or cucumber slices.
- Add a splash of pure cranberry or tart cherry juice.
- Switch to unsweetened teas—black, green or white if you’re looking for caffeine—or herbal teas, which are naturally caffeine-free. Tea comes with other great health benefits.
- If you’re not on a potassium restricted diet, try coconut water which is high in potassium and other nutrients.
- Boil water with fresh ginger root, one of Alison’s favorite tips. Once the batch is cooled, you can keep it in the fridge and enjoy it over the next couple of days.
- It’s OK to choose low-sugar sports drinks containing electrolytes if you’ve been very active in the heat. (Alison suggests low sugar unless you’re an athlete exercising intensely for a period of over 60 minutes.)
Avoid drinking alcohol, which can be dehydrating and impair your judgment. Also steer clear of sugar-sweetened beverages like energy drinks, sodas, or sweet tea, which are high in unnecessary calories.
3. Remember to Eat
Food is another way to replenish salt and other important electrolytes. “You often hear advice about limiting sodium in your diet, especially if you have high blood pressure. But you do need some salt for your body to stay balanced, which means replacing what you’ve lost through sweat,” Alison explains.
Choose light, simple snacks and meals that don’t require much cooking. Alison recommends trail mix with nuts for plant-based protein and a little salt, plus dried cranberries or raisins for sweetness. Electrolyte popsicles can also hit the spot, much like a sports drink.
“Keep in mind that eating foods high in water content can also help keep you hydrated,” she adds. “Think veggies like celery, fruit such as watermelon, and cold soups like gazpacho.”
4. Take Time to Pee (and Pay Attention)
As a rule of thumb, staying well-hydrated means going to the bathroom at least every two to three waking hours. Yes, this is one of life’s little annoyances, but it can offer clues as to how your body is coping in the heat.
“Your urine should be about the shade of light lemonade,” Alison tells us. “If it’s darker yellow than that, drink more water; if it’s lighter or clear, you can cut back a bit.”
5. Rearrange Your Schedule
In the intense heat, if you must be outside for more than a few minutes, try to do so when it’s cooler, ideally before 10 a.m. or after 6 p.m.
If you’re out in peak sun, take frequent breaks inside or in the shade.
6. Wear Loose, Light-Colored Clothing
Lighter, breathable fabrics will deflect heat and allow air to circulate, keeping you cooler. Better yet, throw on a brimmed hat to protect your head and face.
7. Keep Your Home Cool
Almost half of heat-related deaths occur indoors, so you need to take precautions to stay safe inside, too.
Close or lower the blinds to block direct sunlight during the day.
Turn off unnecessary electrical devices and appliances that may generate more heat, especially your stove or oven.
If your home gets too hot (above 80 degrees) or you don’t have air conditioning, know where to seek relief. That could be a neighbor’s house, a public building like the library, or a designated cooling center in your community.
8. Listen to Your Body
“Your body is very smart. It will alert you well before you get too overheated,” says Alison. “Dark urine, muscle cramps, and dry mouth are all warning signs you should pay attention to.”
If you notice symptoms, move to air conditioning and sip water as soon as possible. Taking a cool bath or shower can also help.
Don’t rely on fans alone, as they aren’t effective at cooling you off in extreme heat.
9. Check on Vulnerable People
Children, older adults, pregnant women, and people with chronic health conditions such as heart disease, kidney disease, and diabetes are all prone to heat-related illness. They may start showing signs of illness sooner and at lower temperatures.
Watch out for your furry friends, too—pets can also become overheated.
10. Learn the Signs of Heat-Related Illness
Know what to do if you or a loved one experiences the signs of heat exhaustion or heat stroke, which is a medical emergency. These include a severe headache, fast pulse, nausea or vomiting, and fainting. Learn more about heat-related illness from the CDC.
Beat the Heat
Heat-related illness is serious, but also largely preventable. Take these tips to heart so you can safely enjoy the best of the season. When summer gets sweltering, a little planning goes a long way.
More resources:
- Extreme Heat Preparedness Checklist (American Red Cross)
- Preventing Heat-Related Illness (CDC)
- Symptoms of Heat-Related Illnesses (CDC)
- Heat-Related Illness Infographic (CDC)
Note: Since everyone’s health history and nutritional needs are so different, please make sure that you talk with your doctor and a registered dietitian to get advice about the diet and exercise plan that‘s right for you.