The dog days of summer are upon us, and unfortunately, the increases in heat and humidity also increase your risk of heat-related illnesses.

“Humidity exacerbates the effect of heat on the body,” explains Dr. Michael Lakes, emergency medicine specialist at Kettering Health Network. “When the ambient temperature is 95 degrees or more, the body can no longer radiate its own heat to cool itself.”

Types of heat illness

Minor heat-related illnesses include swelling in the lower extremities and hands, which occurs when the body tries to dissipate heat by expanding blood vessels. Another is prickly heat (a rash on the feet or other clothed area), which occurs when blocked sweat glands rupture, breaking the skin.

Heat exhaustion—a more serious condition—occurs “when the body responds to prolonged heat exposure with loss of sodium or water or both during sweating,” Dr. Lakes explains. Symptoms include headache, nausea and vomiting, dizziness, muscle cramps, malaise and fatigue, and fever less than 104 degrees.

“Heat exhaustion can progress to heat stroke, which can be fatal,” Dr. Lakes warns. “Heat stroke has all the features of heat exhaustion plus altered mental status, often with a body temperature higher than 104 degrees.”

Am I at risk?

Anyone can develop heat illness, but some individuals are more susceptible.

“Children are especially vulnerable,” says Dr. Lakes. “Unfortunately, heat stroke in children often occurs when they’re left unattended in a vehicle, where temperatures can reach 140 degrees in just a few minutes on a hot sunny day.”

The elderly are at risk because of decreased ability to sweat or to sense temperature changes—especially if there is concurrent dementia.

Certain medications also impair the body’s ability to respond to heat stress, so ask your provider about any medications you take.

Beat the heat

Dr. Lakes offers these tips for preventing heat illness:

• Stay hydrated. “Drink plenty of water, especially before you get thirsty. If exercising or engaging in heavy labor, drink an electrolyte solution like Gatorade. Avoid alcohol.”
• Remove yourself from the hot environment. “If you don’t have air conditioning, resting in an air-conditioned place for as little as two hours a day can decrease the likelihood of heat stroke.”
• Wear light, loose clothing.
• Increase carbohydrates and decrease proteins during periods of high heat.
• Athletes should acclimatize to practice in high heat environments gradually over a period of 1-2 weeks, and exercise heavily during only the coolest parts of the day.
• Avoid direct sunlight and take advantage of the shade.

When to seek help

If you or someone you’re with has signs of heat stress, encourage fluids and seek shelter in a cool place. If someone becomes confused or loses consciousness in a hot environment, call 911 immediately.