If you’re engaging in outdoor sports this summer, the toughest challenge you encounter could be the heat. High temperatures and humidity can increase the stress on your body to dangerous levels. Make sure you have a game plan to break a sweat safely.

Getting Used to the Heat

Your body needs time to adjust to the heat in conditions specific to your sport, known as heat acclimatization. According to the National Athletic Trainers’ Association (NATA), acclimatization is one of the best ways to prevent exertional heat stroke (EHS), which can be fatal.

EHS occurs when your core temperature is heightened to dangerous levels (typically above 105 degrees) during activities in hot, humid conditions, overwhelming your body’s ability to cool itself.

NATA recommends a seven-to-14-day progressive adjustment period in the heat, gradually adding necessary gear while lengthening time and intensity. This can help you avoid EHS and other heat-related illnesses such as heat cramps.

Once your body is acclimatized, you’ll respond better to the stress of your sport in hot conditions. For example, you’ll begin sweating more quickly to cool your body. And your cardiovascular system will become more efficient, leading to better blood circulation, an increase in blood plasma and a slower metabolic rate.

These adaptations keep you safer in the heat while giving you a performance edge.

But be aware that if you stop being active in the heat for a few weeks, you’ll lose these benefits.

How Hot Is Too Hot?

To understand how hot you will feel outside, check the heat index, which considers both temperature and humidity.

The National Weather Service’s heat index chart can help you determine when to be cautious, when to shorten the time and intensity of your activity and when to cancel it altogether. Be aware that the heat index assumes there is some shade. If you are in direct sunlight, the heat index can increase by much as 15 degrees.

For details on even more specific conditions for your location, check out the HeatRisk tool from the Centers for Disease Control and Prevention (CDC), which assesses the risk of heat illness based on your ZIP code. This site also reports on air quality, which can worsen in the heat and cause coughing or shortness of breath.

If possible, plan activities for the early morning or evening, when the heat is typically less intense. Protect your skin with sunblock – and wear light-colored, loose-fitting clothes if possible.

Hydration and Breaks

Keeping up your fluid intake is critical when the sun is blazing, but you should start before you venture outside. By the time you feel thirsty, you are already partially dehydrated.

The American Medical Society for Sports Medicine says you should drink 20 ounces of water or a sports drink one to two hours ahead of activity – and you can consider adding another 10 ounces of fluids 15 minutes before you begin.

If you are working in the heat (which can be as intense as some sports), the CDC says drinking smaller amounts at shorter intervals is better than drinking a lot less frequently (suggested amount: 1 cup or 8 ounces every 15-20 minutes).

However, the agency also warns not to drink more than 48 ounces or 1 ½ quarts per hour. Drinking too much fluid can cause a medical emergency if the salt concentration in the blood becomes too low. You must also eat regular meals to replace salt lost in sweat.

Be aware that alcohol and caffeine can cause dehydration.

The Warning Signs

Whether you’re monitoring yourself, a friend or an entire team, it’s important to know when the heat is too much. The signs of heat illness are:

• Muscle cramping
• Dizziness
• Headaches
• Atypical heavy sweating
• Weakness
• Shortness of breath
• Nausea

Cool Immediately – and Seek Help!

If someone appears to be in danger, immediately move them out of the heat, begin cooling them and call 911. NATA recommends immersion in icy cold water, if possible. Only after cooling should the person be transported to the hospital.

Know Your Personal Risk

Make sure to know if you are predisposed to react more strongly to playing sports in the heat because of a preexisting condition, your age, medications or any other factor. Just like a student needs a physical before participating in a school sport, it’s important that you have regular checkups to ensure your safety during exercise, especially in the heat.

Sources:
Centers for Disease Control and Prevention
National Athletic Trainers’ Association
National Weather Service