Stay healthy and cool during the heatwave

The triple-digit temperatures forecast for this week can expose people to dehydration, heat exhaustion and even heat stroke. UC Davis Health occupational and environmental medicine physician Sheri Belafsky and sports medicine physician Brandee Waite offer tips to beat the heat and stay cool and healthy.

• Drink before you're thirsty—Thirst is often the first sign of dehydration. Belafsky recommends those who work outdoors drink one quart of water per hour. Those who work indoors should consider setting a "water alarm" to remind them to stay hydrated.
• Acclimate yourself to the heat—"It can take a few weeks to acclimate your body to the heat," Belafsky said. "Be mindful and recognize that your water requirements will increase." Keep visitors in mind, Waite added, especially as COVID-19 restrictions are lifting and more people are traveling. "Out-of-town visitors may not be accustomed to our triple-digit temperatures and should especially take it easy the first few days," she said.
• Skip the caffeine—"It's tempting to reach for a soda or iced tea on a warm day to quench your thirst," Belafsky said. "But people aren't aware that the caffeine they're consuming is doing the exact opposite of what they need. It's dehydrating." Instead, she recommends opting for herbal iced tea that's decaffeinated, sparkling water, or creating your own "spa water" infused with fresh fruit.
• Exercise indoors or during the coolest parts of the day—"People who exercise regularly often don't consider the effects of heat on their performance and overall health," Waite said. While right after work is a common time to exercise, this is typically the hottest time of day. Make sure to do it during the cooler morning and possibly evening hours.
• Wear breathable fabrics—Try wearing lightweight cotton, linen or a blend that feels cool to the touch and is breathable. Avoid synthetic fabrics like polyester that don't allow the body's natural cooling system to work. If you'll be in and out of buildings with air conditioning, Belafsky suggests wearing light layers.
• Take regular timeouts amid outdoor activities—"Schedule a minimum of 10 minutes in the shade for every hour of exercise or activity," Waite said. "Children, older people and those who are less fit need more rest." She notes that youngsters aren't always aware that they need rest periods and water breaks.
• Know your personal risk—"Certain populations are more vulnerable to the heat," Belafsky said. "People with chronic kidney disease or diabetes, for example. It's important to understand how extreme temperatures affect your medical condition." Belafsky also shared that common medications can impact a person's ability to stay cool or hydrated. Thyroid medication and diuretics that treat blood pressure can cause excessive sweating and salt depletion that leads to dehydration. Beta-blockers for heart conditions can impair sweating which makes it hard for the body to cool itself.

Heat-related illness

"Heat-related illness can rapidly lead to a medical emergency, so it is essential to take action at the first warning signs," Waite said.

Heat exhaustion and heat stroke often occur in people working hard or exercising in hot weather, but they can happen to anyone on a hot day. People especially at risk are the elderly, children, overweight or obese individuals, and those with heart conditions or taking certain medications such as diuretics (also known as water pills).

• Heat exhaustion is an early stage of heat stroke. The person feels excessively tired, weak, and nauseous, and may feel dizzy and even briefly pass out. The skin is cool and clammy and may appear either flushed or pale. Have the person sit or lie down in a shady location and give cool drinks—the colder, the better. Try anything to cool the victim down: Loosen or take off extra clothes, sponge with cold water, and place him or her near a fan. If the person does not get better or symptoms get worse, seek medical care immediately.
• Heat stroke is a very dangerous condition. The body stops sweating, and the internal temperature climbs to high levels, although the person may get what feels like chills. The skin may be quite dry and hot. People with heat stroke may be confused, agitated and have blurry or double vision. Have the person lie down and call 911 at once while others continue efforts to cool the victim down. They may also lose consciousness.