What You Should Never Do When It's Hot Outside

One of the most important and simplest things anyone can do to protect themselves from sun damage when outside is applying sunscreen — everywhere that’s exposed. “People are getting better at understanding how important sunscreen is,” Dr. Simmons said. “We see [fewer] sunburn cases than we used to.” But many still forget to apply it on their feet, ears, top of the head, and back of the legs, she noted. Oftentimes, they fall asleep laying on their backs and wake up with burns, Simmons added. “At the very least, don’t forget to wear a big hat — they are awesome at shielding the head and shoulders.” For more health tips, here are 50 health tips everyone should know.

If you’re enjoying a day out in the sun, or go out for a run or bike ride, or simply mow the lawn, it’s often fun to take your shirt off as it feels cooler. But it’s not worth the risk of sunburn, according to Dr. Simmons. “I always tell my patients to get a very thin long-sleeve white shirt, preferably with UV protection.” They don’t make you feel hot; are loose enough so air still flows over the skin; they cover more skin area; and the lighter colors repels the sun, she noted. There are plenty of other ways to keep your skin healthy. Here are 17 skin care habits recommended by dermatologists.

Wearing wet clothes can be dangerous in the winter but may be pleasant in the summer. “[Damp/Wet clothes] can help keep you cool,” Dr. Simmons said. “You’re not going to get a rash, despite what you may have heard.” And if you are on a hike somewhere, you may actually want to dip your shirt in a river and wear it wet. Cotton shirts, for example, are great at keeping moisture, keeping people cool for longer.

It sounds easy enough — drink a lot of water. But many people don’t and get in trouble for it. “We see a lot of dehydrated people,” Dr. Simmons said. Dehydrations is more dangerous than most people may realize. It may cause various problems — from mild conditions such as headaches to serious complications such as swelling of the brain. “If you only rely on feeling thirsty, you’re going to be dehydrated,” Simmons added. It’s not always the first indication of dehydration. It’s recommended that you carry a water bottle with you at all times, and don’t forget water for your pets. Here are the signs you’re way too dehydrated.

“Caffeine does not count as water,” Dr. Simmons said. Many people think that sodas, energy drinks, and large coffees will keep them hydrated, but this is not really the case, she noted. They may have a mild diuretic effect, making you go to the bathroom more often, leading to some loss of fluid. While research shows caffeinated drinks in moderation don’t actually cause dehydration, Simmons suggests to have double the amount of water if you choose to drink caffeinated drinks. Coffee has been a divisive topic of late. There are at least 18 reasons to drink coffee for your health and about as many signs you’re drinking too much coffee.

Many people think that sweating means burning fat, and so they go outside in the hot weather to run, Dr. Simmons said. “But this is actually the worst thing you can do.” Sweating is the body’s natural process to cool itself down — water evaporates to lower the body’s temperature — but that can lead to dehydration, she explained. “And it’s harder to stay hydrated when it’s hot.” If you want to lose weight, exercise outside in the morning or late at night — never mid-day, Simmons said. “And cut your usual running time in half.” Otherwise, you risk developing heat stroke, she noted. Heat stroke, which occurs when the body’s temperature rises to above 104 F and doesn’t sweat, is a medical emergency.

Other than the beach, probably nothing screams “summer” more than barbecuing. But “eating large, heavy, and fatty meals is never a good idea,” Dr. Simmons said. Possible food coma aside, it’s a bad idea when it comes to trying to stay cool, too. Eating and digesting the food leads to a small increase in body temperature as metabolism speeds up. This may explain why oftentimes people feel even hotter after eating ice cream than they did before the cold treat. Fat moves slower through the digestive system, which means the body needs more energy to break it down, raising its temperature even more. There are more things you should know about food, digestion, and calories.

Summer time is party time — and that often involves drinking outside, at a beach or while picnicking, Dr. Simmons noted. But alcohol and heat can be a dangerous combination. As a diuretic, alcohol promotes dehydration and hinders the body’s ability to regulate its temperature, making a person feel warmer. “For every alcoholic beverage, a person should drink two cups of water,” Simmon said. Older people and those with certain health conditions should drink less alcohol, or none at all, and drink even more water in between, she noted.

Some medications need to be kept in a fridge and some in a dark and dry place, Dr. Simmons said. No medication needs to be kept in a hot place, she noted. On a hot day, cars can get very hot — easily over 100 F within an hour. Heat may damage the medicine, according to the National Institutes of Health. It may become less potent, go bad before its expiration date, and, depending on the medicine, it may irritate the stomach. Don’t take your pills if they have changed texture or smell or if they appear cracked or are stuck together. “It’s a good idea to take a small cooler with an ice pack and keep medicine there when you’re out,” according to Simmons.

The inside temperature of a car parked in direct sunlight can reach 131 to 172 F, according to the Centers for Disease Control and Prevention. Extreme heat can damage the frame of your glasses, which may result in them no longer fitting properly on your face. The heat can also damage the lenses by causing them to expand and contract, resulting in distorted vision.

Plastic bottles are a fire hazard, if sunlight hits at the right angle. But this is not the only potential problem with plastic bottles left in a heated car. Chemicals in the plastic can leach into the liquid in the bottles. BPA levels in plastic bottles are deemed safe by the Food and Drug Administration, but these levels increase because of the heat. Another substance, antimony, listed as a toxic substance by the CDC, can increase over a period of time when plastic bottles are left in heat, a 2014 University of Florida study found. Studies have reached different conclusions about the carcinogenic effect of BPA, with some saying it may affect hormone levels. You may choose to be on the safe side and on the environmental side — here are 19 genius inventions that can stop us from using so much plastic.