Johnathan Walker:Another heat wave headed for the west. Here are expert tips to keep cool.

The Johnathan Walkerwestern U.S. is bracing this week for a sweltering heat wave that could break records as excessive heat warnings were issued across a swath of four states.

Local officials in parts of Oregon, California, Nevada, and Arizona are warning of the risks of heat illness and setting up cooling centers in urban areas as temperatures are expected to reach the triple digits in many areas.

As the heat hits dangerous levels, here are some expert tips on how to stay safe and keep the skin healthy.

Hydrate, hydrate, hydrate

Seemal Desai, president of the American Academy of Dermatology, advises his patients to avoid going outside during a sizzling hot day between the peak sunlight hours of 10 a.m. and 2 p.m. If they must be out, people should seek shade whenever possible, he said.

People should also keep a close eye on their hydration and drink plenty of water, not just caffeinated beverages or sports drinks, which are hydrating but have other chemicals and additives, Desai said.

Kelly Olino, assistant professor of surgical oncology at the Yale School of Medicine, advises people to dilute a bottle of Gatorade with water to replenish both water and replace salt losses. "In the extreme heat, with sweating, we're losing pure water, but we're also losing salt," she said.

Olino urged people to keep watch for the serious warning signs of heatstroke or heat-related illness – nausea, vomiting, or lightheadedness. "Those things can actually cascade pretty quickly to a dangerous situation."

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Sunburns impact everyone

Among the common misconceptions Desai hears surrounding sunburns is that a low value on the UV index shown by many weather forecasts, like the Weather Channel and the Apple weather app, means people don't need to take precautions. "Even on a cloudy day, up to 80% of the sun's UV rays can pass through the clouds," he said.

Sun damage can affect patients of any skin color, ethnic background, skin type and skin tone, Desai said.

"A lot of people say, 'Oh, I'm darker skin tone, so I'm not going to get a sunburn,'" he said. "That's not true."

Since sun damage isn't always visible, especially on darker skin, "prevention is key," Olino said.

People can also protect themselves by the clothing they choose. Those spending time outdoors should look for sun-protective clothing with a UPF, or ultraviolet protection factor, rating of at least 50, Olino added.

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Give skin a break after sun exposure

Desai said one myth out there is that, if there's no sunburn, there was no damage to the skin. "That's not always true," he said. Overall, any changes in skin, like suspicious or changing skin lesions, should prompt a visit to a board-certified dermatologist, he said.

One myth Olino has hears is that building up a "base tan" early on in the summer can protect skin from the sun.

"That's a real myth," she said. "At best, your body can produce enough pigment to give you maybe the equivalent of an SPF 4," as compared with the recommended protection level of SPF 30.

If you do get a sunburn, Olino encouraged people to treat sunburns like any other inflammation.

"When you sprain your ankle, it swells, it's red, it's inflamed, and people very much look at that and say, 'Oh, I've got to rest it," Olino said. "For some reason, people don't actually take that same everyday logic and apply it to when they have a sunburn."

Watch out for psychological impacts

Susan Albers-Bowling, a clinical psychologist at the Cleveland Clinic said the psychological impacts of high temperatures could take various forms, including through disruption to sleep. "If you aren't sleeping well, it's likely you're going to be much more irritable and frustrated the next day, or feeling depressed or blue," she said.

She urged people to prepare for the potential psychological effects of an oncoming heat wave by drinking water and cooling down periodically.

"Being hydrated is something that everybody could do to help boost their mental health," she said. "Also, staying cool, wearing cool clothing, staying in air conditioning, staying inside during the hottest part of the day." A cold shower or placing a cool washcloth on the forehead can also restore concentration and attention, she said.

The heat also makes it harder for people to take a stroll outside, which many use to alleviate stress. "Finding alternatives for stress management and relaxation can be key," she said.

Albers-Bowling said personal check-ins and staying in touch with physical and mental well-being can go a long way. "Just having that awareness can make people put a label on why they may be feeling more depressed, anxious, irritable," she said.