High school sports teams will soon begin practicing in what has been an extremely hot summer for much of the country. Now, before they hit the field, it’s time for athletes to slowly and safely build strength and endurance.

Research has shown that the greatest risk of heat illness occurs in the first two weeks of team training, while players’ bodies are still adjusting to the physical exertion and heat. Being physically ready to start increasingly intense team training can help reduce the risk.

I am an athletic trainer specializing in catastrophic injuries and heat illness. Here is what everyone needs to know to keep athletes safe in the heat.

Why should athletes resume training slowly?

One of the biggest risk factors for developing dangerous heat illness is your physical condition. That’s because your condition affects your heart rate and breathing, as well as your ability to regulate your body temperature.

If an athlete waits until the first day of training to begin exercising, their heart cannot pump blood and oxygen as effectively throughout the body, and the body is not as good at dissipating heat. As a person trains more, their body undergoes changes that improve thermoregulation.

Therefore, it is important that athletes increase their activity gradually and safely, ideally starting at least three weeks before team training begins.

There is no hard and fast rule for how much activity is good for preparation. It varies from person to person and from sport to sport.

It is important to remember not to push yourself too hard. It takes time to get used to training in the heat, so start slowly and pay attention to how your body reacts.

How hot is it to exercise outdoors?

Anything warmer than normal can be risky, but that varies by country. A warm day in Maine can be a cool day in Alabama.

If it is significantly warmer outside than you are used to, you are more likely to suffer from heat illness.

To stay safe, avoid exercising outdoors during the hottest periods. Exercise in the shade, or in the early morning or evening when the sun’s rays aren’t as hot. Wear loose clothing and light colors to dissipate and reflect as much heat as possible.

Hydration is also important, both drinking water and replacing electrolytes lost through sweat. If your urine is light colored, you are probably hydrated. Dark urine is a sign of dehydration.

What does acclimatization look like for teams?

Once team practices begin, many states require heat acclimation processes that are added gradually to the activity, although their rules vary. Some states require 14 days of heat acclimation. Some require six days or none at all. Some require it only for football.

Athletes who have a head start on acclimatization can help their bodies adapt to the heat more quickly and efficiently. Regardless of what your state requires, all athletes participating in any sport should carefully acclimatize.

To acclimate to the heat, you should add more load to your training every few days. Be careful not to add too much load.

For example, instead of players starting the first day of practice in football with full protection and full contact, players might start the first few days with helmets only.

Acclimatization is also about boundaries: Training only once a day at first and limiting the number of hours players train each day can help prevent their bodies from being overtaxed too quickly. Coaches and athletic trainers should also monitor wet-bulb temperature—the combination of heat, humidity, radiation and wind speed—to assess heat risk to players and know when to limit or cancel training.

This isn’t just true for football. Whether it’s soccer, track, softball or baseball, heat illness doesn’t discriminate. A Georgia basketball player died after collapsing during an outdoor practice in 2019. She was used to training indoors, not in the heat.

What are the warning signs that an athlete is overheating?

If a player becomes slower or lethargic, it could be a sign that he is overheating. You may see signs of central nervous system problems, such as confusion, irritability, and disorientation. You may see someone stumbling or struggling to hold themselves up.

Usually, someone with exercise-induced heatstroke will sweat. They may have red skin and sweat profusely. Sometimes, a person with heat stress may lose consciousness, but usually not.

What should you do if someone seems to be suffering from heat?

If someone appears to be suffering from heat illness, cool them down as quickly as possible. Find a pool where you can put the person in with water and ice. Keep their head out of the water, but cool them down as quickly as possible.

Immersion in a cool bath is best. If you can’t find a bath, put them in a shower and put ice around them. Even a tarp will work – athletic trainers call it the taco method: place the patient in the middle of the tarp, put some iced water in it, and hold the sides up to slowly vibrate them, moving the water from one side to the other.

Every sports team should have access to a cold storage tank. About half of states require it. As that expands, these safety practices will likely trickle down to youth sports.

If a player appears to be suffering from heatstroke, cool him or her down and call 911. A comprehensive emergency plan ensures that all staff members know how to respond.

What else can teams do to prepare?

Heat stroke from exertion is a leading cause of death in athletes at all levels. But proper recognition and treatment can save lives.

Athletic trainers are essential to athletic programs because they are specifically trained to recognize and treat patients with heat stroke and other injuries. As hot days become more common, I believe all athletic programs, including high school athletic programs, should have an athletic trainer on staff to keep players safe.

Samantha Scarneo-Miller, assistant professor of athletic training, West Virginia University

This article is republished from The Conversation under a Creative Commons license. Read the original article.