The heat this summer is breaking records across the world and in the United States, and being outdoors in extreme heat can take a toll on your body. Reporting for NPR's "Shots," Allison Aubrey and Carmel Wroth outline eight things experts say you should do when out in the heat.

8 things to do when out in the heat

1. Make sure to acclimate to the heat

When it gets hot outside, your body needs time to adjust, according to Neil Gandhi, a physician at Houston Methodist Hospital. "You can't do too much too soon."

If you go from spending time inside in the air conditioning to immediately doing an outdoor activity in the heat, your body won't be "acclimatized to handle the stress," Gandhi said.

If you're planning on spending time outside in the heat, plan to spend short periods of time outside each day leading up to your outdoor activity. "[Acclimatizing is] going to happen over the space of several days of exposure," said David Eisenman, a physician at the University of California, Los Angeles and co-director of the UCLA Center for Healthy Climate Solutions.

Once your body is acclimatized, it gets better at fending off heat-related illnesses. "Our body starts to sweat sooner at a lower body temperature and at a greater rate," Eisenman said. Blood flow to the skin also improves, which carries heat out of the body's core and cools you down.

Eisenman also notes that children acclimatize to heat much more slowly than adults, so give them more time to prepare.

2. Get hydrated and stay hydrated

According to Wafi Momin, a cardiologist at Memorial Hermann Health System, you should hydrate before you go outside in the heat. "Grab a glass of water or a sports drink before you head out to the outdoors," he said.

Make sure you bring lots of water with you, and drink it before you start feeling thirsty. "The moment you begin to feel thirsty, you're likely anywhere between 10 to 25% dehydrated already," Gandhi said.

Eisenman noted that most people aren't well-hydrated on a normal day, so it's easy to start off a hot day at a deficit. He recommends doubling the amount you drink in a normal day, and paying attention to the color of your urine to determine how hydrated you are. "Make sure that you're peeing frequently and that your urine is pale," he said.

And according to John Schumann, a primary care physician and medical director at Oak Street Health, sports drinks can add electrolytes and can be useful if you're overheated or participating in an endurance event, but are unnecessary if you're just trying to stay hydrated during the day.

3. Remember that cars heat up quickly

According to Eisenman, cars heat up fast because of a "mini greenhouse effect."

"The sun is coming through those windows, and then the heat is getting bounced around and getting trapped inside. It turns into a different wavelength of heat and doesn't go back out the windows," he said. "And on a day of moderate temperatures, say like 75 degrees outside, in 25 minutes it will become 100 degrees inside your car."

Around 50 children each year die from being left in a hot car, so don't underestimate how dangerous a hot car can be, especially if you're distracted finishing up a phone call, Eisenman said. "Even with the air conditioning running, even with the windows cracked, it can become hot in there very quickly," he said.

4. Remember certain medications don't mix well with heat

Some medications can make people more vulnerable to heat, Momin said.

For example, some heart medications like blood pressure drugs are diuretic. "Those medications are trying to get rid of fluid from your body because of underlying heart issues," Momin said. If you add heat on top of that, which also causes you to lose fluid, "that can cause a very dangerous situation."

Other medications can have a similar effect, Schumann said, including anticholinergic medications, anticonvulsants, bladder medications, and sedatives. "Lots of medications work by dehydrating us — excreting excels fluid. Be careful!" he said.

5. Don't ignore the signs of heat-related illness

Early signs of being overheated include sweating, fatigue, dizziness, and headache, as well as nausea or lightheadedness, all of which can be easy to ignore.

"You may just blow it off, saying, you know, it's hot and I've felt this way before, but the worst of the symptoms can come on very quickly without realizing it," Momin said. "And all of a sudden, your body's overheating to a point where you won't really be able to drink enough fluids at that juncture to reverse what's already gone on."

Heat exhaustion symptoms can quickly become more serious and can include muscle cramping, increased fatigue, and accelerated heart rate. "You may start to weaken and just kind of get out of breath as you exert yourself," Gandhi said.

6. Know when medical attention is necessary

If you're with someone who starts showing signs of a heat-related illness, move them to a cool place, give them water or a sports drink, moisten their skin, and remove any unnecessary clothing like shoes, socks, or jackets, Aubrey and Wroth report.

According to Eisenman, their symptoms should improve in about 30 minutes. If they don't, or if they start having more concerning symptoms, call for help. "I think sometimes people wait too long to call 911," Eisenman said.

"If their heart rate is going fast, if they're breathing quickly, if they seem at all confused, those are all indicators they've had more exposure to the heat than you can handle," he added.

Once heatstroke hits, people can pass out, and if that happens, seek immediate medical attention.

7. Wear loose, light clothing

If you're out in the heat, make sure you're wearing clothes that fit loosely and are light-colored. Also, avoid tight-fitting clothes, as they can block airflow.

"I would seek lighter colors because those tend to reflect heat rather than absorb heat compared to darker colors such as blacks and dark blues," Momin said.

"Loose-fitting clothing allows for the heat to evaporate off your body more easily," Eisenman added.

8. Avoid alcohol

If you're out in the heat, experts recommended avoiding alcohol. "Alcohol will dehydrate you much faster" in the heat, Schumann said.

If you are drinking in the heat, "drink some water for every drink you have to avoid trouble," Schumann said. "If you wind up having to pee a lot, it'll be worth it. If you don't, you might be getting into trouble."

"Alcohol is very problematic" if you're out in the heat, Momin said. Not only does it cause your body to lose fluids, "it can also impair your judgment," which could lead you to miss signs of heat-related illness, Momin added. (Aubrey/Wroth, "Shots," NPR, 7/12)