The heat is on, and high temperatures are breaking records around the world. While you want to enjoy outdoor summer fun, it’s important to be prudent and take extra precautions to avoid illness and even potentially deadly heat stroke.

Even though all heat-related deaths and illnesses are preventable, each year an average of 658 people die from extreme heat, and experts say that number may be even higher due to underreporting by hospitals and health officials. Statistics show that almost all heat-related deaths occur between May and September with the highest numbers reported during July, says the Centers for Disease Control and Prevention.

Here are ways to stay safe this summer:

• Take it slow. According to NPR, your body needs time to acclimatize to extreme heart. Once you get used to the higher temperatures, you sweat more and blood flow to the skin improves, which has a cooling effect. If you are planning a camping trip, summer sightseeing or any other extended exposure to heat, spend short periods of time in warm weather outdoors each day leading up to your getaway.

• Hydrate in advance. Drink a glass of water or other hydrating beverage before going outdoors and bring plenty of water with you. Don’t wait until you are thirsty to drink, because at that point you may already be dehydrated. The best test for hydration is checking the color of your urine. It should be pale yellow or clear.

• Check your medications. Prescription drugs such as blood pressure medicine that acts as a diuretic can cause you to lose excessive amounts of fluid in the heat. Other types of medications also have this effect, including anticholinergic drugs, anticonvulsants, bladder medications and sedatives. Older people in general are more vulnerable to heat. Ask your doctor whether any of your medications could be dehydrating, says NPR.

• Watch for signs of heat related illness. According to MedPage Today, heat exhaustion can develop even several days after exposure to extreme heat.  The Mayo Clinic adds that prolonged periods of exercise can lead to heat exhaustion’s progression over time, instead of a sudden onset. Symptoms of heat exhaustion include muscle cramping, increased fatigue, and accelerated heart rate. For heat-related emergencies, rapid cooling is the standard of care: removing clothing, immersion or dousing in cold water, applying ice packs, fanning, elevating feet, and monitoring airway and breathing. Seek medical help if the symptoms do not subside or become worse.

• Wear loose, light clothing. Dark colors, such as black and navy, absorb more heat so stick to light colors that reflect heat. Stay away from tight clothing, which can block airflow, says NPR. “Loose-fitting clothing allows the heart to evaporate off your body more easily,” says Dr. David Eisenman, of UCLA Fielding School of Public Health.

• Avoid alcohol. If you attend an outdoor party, indulge in a mocktail, and shun alcoholic beverages. “Alcohol will dehydrate you faster in the heat,” notes Dr. John Schumann, an internal medicine specialist in Tulsa, Okla.  But if you are determined to drink an alcoholic drink, have a glass of water for every beverage you consume. Experts warn that drinking alcohol can impair your judgment so you may ignore the symptoms of heat-related disease.

• Be careful in your car. Cars heat up fast during warmer weather because of a “mini greenhouse effect,” says Eisenman. The sun’s rays come through the windows and get trapped inside raising temperatures dangerously high even in moderate weather.