Q & A: Staying Safe in Extreme Heat

Mary Barron of the Milken Institute SPH and Anna Rubin of SMHS and GW MFA talked hydration, symptoms of dangerous heat exposure and more.

July 17, 2024

Summer scene of water feature in a city park

A water-misting device offers a chance to cool in a city park. (Adobe Stock)

If you’ve been hoping for picnics, hikes and park playdates this summer, you may be thinking twice. Washington, D.C., is experiencing record high temperatures, with the heat index reaching as high as 110 degrees and the area currently under an excessive heat warning during peak sunlight hours.

GW Today spoke to Anna Rubin, assistant professor of medicine at the George Washington University School of Medicine and Health Sciences and a primary care specialist with GW’s Medical Faculty Associates, and Mary J. Barron, associate professor of exercise and nutrition science at the Milken Institute School of Public Health, about the best ways to stay safe and healthy when it’s dangerously hot outside. (Short version: Stay indoors whenever possible, hydrate more than you think you need to, and check in with vulnerable community members as best you can.) Conversations have been edited for length and clarity.

Q: From a medical perspective, what constitutes “extreme” heat?

ANNA RUBIN: Extreme heat occurs in the summer and means extended temperatures that are hotter, and often more humid, than the average for a given location. In D.C., heat is considered extreme and the Heat Emergency Plan is activated when the heat index (what the temperature feels like to the body when relative humidity is combined with air temperature) reaches 95 degrees.

Q: What does someone new to Washington, D.C., need to know about our kind of heat?

MARY BARRON: It’s extremely humid here, and that humidity really affects sweat evaporation, which is our main mechanism of cooling. When it's humid, we sweat a lot but don't evaporate that moisture, so it doesn't take the energy or the heat away from us. Even people who are extremely fit will feel the effects. Don’t underestimate how it can affect you even if you’re used to being physically active in the summer.

Q: What are the most important tips for staying safe in extreme heat?

AR: Stay indoors in air conditioning as much as possible. If you don't have A/C, take cool showers or baths, drink plenty of water and make sure you have a buddy who can check on you (and vice versa).  If you do not have access to a cool-temperature location, visit one of D.C.'s cooling centers located throughout the city.

If you must be outdoors, limit sun exposure and avoid hard work at peak sun and heat times (10 a.m. to 3 p.m.). Take frequent breaks and encourage others to do the same.

MB: Hydration is crucial. You should not go anywhere without a water bottle. Make it easy for yourself—some people don’t like to drink plain water, so it’s fine to add hydration packets or substitute a sports drink. If drinking strawberry Gatorade throughout the day is what it takes to get water into your body, great. Energy drinks are a big no-no! In general, avoid caffeine and alcohol or cut way back. They are diuretics, so they will affect your body’s ability to reabsorb water.

AR: The body needs electrolytes and salts as well as fluids, so do not skip food or snacks.

MB: Some foods are also hydrating. Cut-up watermelon is great, and it’s in season right now. Kids especially love that. Keep grapes in the fridge—they’re like candy.

When you’re planning meals, think about ways not to cook indoors, because that will heat up the house. Grilling is good, no-cook recipes like salads are good. I like to pick up a whole rotisserie chicken from the grocery store, so I have an easy protein source.

AR: Wear light-colored, lightweight clothing, a hat and sunscreen.

MB: Clothing fabric should be breathable—cotton is great, or any fabric that is wicking, so it brings heat away from your skin. Hats should have a broad brim to keep the sun off. When I have to be outdoors to officiate my kids’ swim meets, I also cover the back of my neck with a gaiter.

Q: What symptoms should people be aware of in the heat? How should you address them and at what point should you seek medical assistance?

MB: Prevention is the most important strategy. Don’t wait until you’re thirsty to drink water. If your mouth is dry, you’re experiencing the mechanism of thirst, that’s alerting you that you are already dehydrated.

AR: Muscle cramps are an early sign of the body struggling to cool down. Headache, nausea, weakness, dizziness, exhaustion and moist pale skin can be signs of heat exhaustion.

Heatstroke is the life-threatening condition to which heat exhaustion can progress, which can present as red flushed skin, confusion and changes in mental status, fast heart rate, fast breathing, vomiting or seizures.

With cramps, headache, weakness or dizziness, stop all activity and get to a cool place. If the symptoms persist, seek medical attention. Any symptoms of heat exhaustion should present to medical care immediately.

MB: Heat-related illnesses are heat cramps, heat exhaustion, and heatstroke. Heatstroke is a medical emergency when the body has lost its ability to cool itself. Getting there is not always linear—some people experience heatstroke without experiencing heat exhaustion. People don’t necessarily feel the early warning signs. So watch out for yourself and your friends. If you feel nauseous or lightheaded, get indoors as quickly as you can. A change in consciousness is an emergency. If someone is behaving strangely or they’re confused, activate emergency medical services.

In less severe cases, if you feel overheated, drape a cold, wet towel around your neck. The head, neck and armpits are the most effective places to apply cold. With my athletes, if I need to cool them down quickly, I put them in an ice bath. A cold shower is a good substitute.

Q: Are any groups particularly vulnerable? What extra precautions, if any, should these people take?

AR: Risk factors for developing heat-related illness include obesity, cardiovascular disease, use of certain medications, pregnancy, alcohol use and dehydration from any cause. Overall, the most vulnerable groups are older adults, young children, outdoor workers and those with chronic conditions or disabilities.

For those at particular risk, avoid time outdoors and lean on family, friends and delivery services to help you with your necessities. Go to a cooling center or public air-conditioned building if you don't have access to a cooled environment. For athletes and those who have to work or exercise in extreme heat, pace your activity and take breaks, drink more water than usual and don't wait to become thirsty. Designate a teammate/buddy and monitor each other’s condition.

MB: If you aren’t an athlete but need to maintain an exercise routine, there are creative ways to do that like walking around an air-conditioned mall, spending a day at a museum or going to an indoor bowling alley. It may be worth looking into a summer membership to a rec center or gym.

If you have elderly neighbors or vulnerable people in your community, check in! When you’re shopping, maybe pick up an extra chicken and some sides for them. If they don’t have air conditioning and you do, invite them over. We have to look out for each other. 


To make an appointment with a physician, visit GW Primary Care or call 202-741-3000.