When summer rolls around, everyone praises the return of longer days filled with sunshine, heat and humidity. This is all great if you’re sitting on the beach with a cold beverage in hand… but not so great if you’re in full athletic gear, running around an outdoor field.

Exertional heat illnesses have become top-of-mind across sports medicine as we step into the muggy months of outdoor sporting events. These don’t just include elite or collegiate athletes either; think of all of the kids playing Little League Baseball or participating in soccer camps. Everyone needs to be taken care of in the hot summer sun, and getting a grasp on how you can best advocate for your athletes’ health and wellbeing during this time is critical now more than ever.

In 2015, the National Athletic Trainers’ Association (NATA) published a Position Statement on Exertional Heat Illnesses to present best-practice recommendations for the prevention, recognition and treatment of exertional heat illnesses and the relevant physiology of thermoregulation. This document outlines years of research and data that give athletic trainers a solid foundation to understand and prevent heat illness. Drink it all in (pun intended).

5 Types of Heat Illnesses

According to the NATA’s Position Statement, there are five distinct heat illnesses that an athlete can suffer:

  1. Exercise-associated muscle cramps: Involuntary, painful contractions of muscle during or after exercise.
  2. Heat syncope: Dizziness that often occurs in unfit or heat-unacclimatized persons who stand for a long period of time in the heat or during sudden changes in posture in the heat.
  3. Heat exhaustion: The inability to effectively exercise in the heat, secondary to a combination of factors, including cardiovascular insufficiency, hypotension, energy depletion and central fatigue.
  4. Heat injury: Moderate to severe heat illness characterized by organ and tissue injury resulting from strenuous exercise and environmental heat exposure.
  5. Exertional heat stroke: The most severe heat illness, characterized by neuropsychiatric impairment and a high core body temperature.

Unfortunately, the variety of causes has made it difficult to produce experimental evidence of exactly what it takes to prevent exertional heat illness. Regardless, the NATA and its panel of qualified professionals have pulled together their top recommendations to stop all five of these conditions before they start. These tips can be broken down into three categories: acclimation, hydration and education.

Heat Illness Prevention Strategy #1: Acclimation

heat acclimation

Just like you wouldn’t ask an athlete to enter a practice or game without warming up, you shouldn’t expect them to start practicing in warm temperatures without adjusting to the heat first. The NATA suggests that developing a pre-season heat acclimation policy should be your first step in heat illness prevention.

“Individuals should be acclimatized to the heat gradually over 7 to 14 days…The first 2–3 weeks of preseason practice typically present the greatest risk of exertional heat illness, particularly in equipment-intensive sports. All possible preventive measures should be used during this time to address this high-risk period” (Casa et al. 2015).

Alongside this policy, a careful medical screening should be administered during pre-season to identify athletes with risk factors. Some of these risk factors include history of heat injuries and a prior muscle, tendon or ligament injury (Casa et al. 2015).

Heat Illness Prevention Strategy #2: Hydration

According to the NATA’s Position Statement on Fluid Replacement for Athletes, establishing pre-exercise hydration, hydration during activity and rehydration protocols is another key staple in preventing heat illness. Here are the NATA’s recommended considerations when building an efficient hydration strategy:

  • Athletes’ sweat rate
  • Sport dynamics
  • Environmental factors
  • Acclimatization state
  • Exercise duration
  • Exercise intensity
  • Individual preferences (Casa et al. 2000).


Getting ahead of hydration issues can prevent them from happening in the first place. “To ensure proper pre-exercise hydration, the athlete should consume approximately 17 to 20 fl oz of water or a sports drink two to three hours before exercise, and 7 to 10 fl oz of water or a sports drink ten to twenty minutes before exercise” (Casa et al. 2000).

Hydration During Activity

It’s easy for both coaches and athletes to get carried away during practices and games; everyone wants to compete, keep up a strong pace and get the most out of every minute. However, not taking breaks to maintain proper hydration levels is extremely detrimental to the health of each athlete, no matter how much of the event they’ve participated in or the environment in which the event is taking place. Just how much should athletes be hydrating? According to the professionals at the NATA, it depends on the sport.

“A proper hydration protocol considers each sport’s unique features. If rehydration opportunities are frequent (e.g., baseball, football, track and field), the athlete can consume smaller volumes at a convenient pace based on sweat rate and environmental conditions. If rehydration must occur at specific times (e.g., soccer, lacrosse, distance running), the athlete must consume fluids to maximize hydration within the sport’s confines and rules” (Casa et al. 2000).

Risk can also depend on the venue or environment that the athletic event is taking place in. If the game is being held indoors, do the facilities have proper climate controls like air conditioning? If outdoors, what’s the weather going to be like? Some athletic programs might brush this consideration to the side because they live in predominantly colder climates, but Tim Kelly ATC, Head Athletic Trainer and Associate Athletic Director at West Point United States Military Academy, suggests that everyone treat hydration protocol like they’ll be playing in the hottest environment imaginable.

“We prepare just like we live in the deep south during preseason for any of the teams that are working out all summer at West Point,” said Kelly. “We’re fortunate at West Point that our athletes are in the field a great deal of the time doing military stuff and it’s drilled into them that hydration is an important part of keeping them healthy and maximizing their training opportunities.”

Kelly’s hydration plan involves many factors, but he most notably stresses the importance of having unlimited beverages available to athletes at all time. To check this off your hydration plan checklist, purchasing gear like the Cramer PowerFlo Pro Hydration Unit gives everyone access to safe hydration on the field. Especially convenient when working in multiple locations and changing fields regularly, this unit has a rechargeable battery and zero-maintenance wheels that never go flat. Portability and stability that can’t be beat! 

hydration unit on field

Lastly, closely monitoring potential dehydration symptoms during activity decreases the incidence and severity of heat illness. These signs include:

  • Thirst
  • Irritability and general discomfort
  • Headache
  • Weakness or dizziness
  • Cramps
  • Chills
  • Vomiting
  • Nausea
  • Head or neck heat sensations
  • Decreased performance (Casa et al. 2000).


Post-exercise rehydration restores any fluid loss accumulated during a game or practice. Ideally completed within two hours, rehydration should contain water to restore hydration, carbohydrates to replenish glycogen stores and electrolytes to speed rehydration (Casa et al. 2000).

Many athletic trainers or team physicians measure hydration with urine color against a color scale. But, an easier (and less invasive) method of hydration measurement is monitoring body weight; athletes should see less than 2% body weight reduction post-activity. Sound complicated? Don’t worry. Mike Harrison ATC, LAT, Sports Medicine Coordinator and Head Athletic Trainer at Allen High School, has gotten his athletes to buy into this method… and it works.

“I think it all starts with educating our athletes,” said Harrison. “I meet with them at the beginning of the year and I use a race car analogy or a truck analogy. My offensive linemen are big-rig trucks and my skill guys are race cars. Both of them burn fuel and I use the gas tank analogy with them. They may come in here on a full tank, but come the next day you might have only replaced ¾ of a tank. If they finish that day up and have only replaced half a tank, then they haven’t been hydrating correctly. So we weigh our athletes in and out everyday in the hot months and for every pound that they lose they have to make that up with 20-24 ounces of fluid. It’s really all about the education.”

He’s right. For your hydration plans to really succeed, you need complete buy-in from the coaching staff and the athletes themselves. Educate your athletes on the effects of dehydration, how to monitor their hydration levels and encourage coaches to help regulate these strategies to cover all of your bases (no pun intended this time). Which leads us to the last strategy…

Heat Illness Prevention Strategy #3: Education

heat illness education plan

You can’t prevent what you don’t understand or aren’t anticipating. As healthcare professionals, it’s essential that athletic trainers take control of their athletic environments and properly inform coaches, athletes, administrators and parents on the signs and dangers of heat illness.

“Down in Florida we do get some heat cramping scenarios, and we do a pretty good job,” said Paul Silvestri MS, LAT, ATC, Head Football Athletic Trainer at the University of Florida. “It’s a team effort. Our nutritional staff does a phenomenal job of staying on top of the guys to get them ready to be out there on the field. Our coaching staff does a good job as well of planning their practices, especially in training camp while we’re not out there in the heat of the day. It’s a collaborative effort.”

Need help getting started? Here are some potential topics that you can cover:

  • Preventing heat illness
  • Recognizing heat illness
  • Treating heat illness
  • Best drinks for hydration
  • Sleep regulations
  • Proper diet
  • How to rest the body effectively

To find data to support these topics, expert advice on heat illness and return to play recommendations, read through the NATA’s Position Statement on Exertional Heat Illnesses. Together, we can all play a huge role in reducing or eliminating these conditions and keep the athletes where they belong; on the field.

national athletic trainers association

Casa, Douglas J., et al. 2015. National Athletic Trainers’ Association Position Statement: Exertional Heat Illnesses. Journal of Athletic Training 50.9: 986-1000.
Casa, Douglas J., et al. 2000. National Athletic Trainers’ Association Position Statement: Fluid Replacement for Athletes. Journal of Athletic Training. 2000;35(2):212-224.

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