Heat Acclimatization Policies

Exertional heat stroke (EHS) is on the rise and is currently among the top three reasons athletes die during sport. Having mandatory state guidelines for heat acclimatization provides a critical standard to protect athletes against exertional heat illnesses, and possibly save lives.

The majority of EHS cases occur during the initial summer workouts when athletes are neither prepared to cope with the environmental conditions nor the new physiological demands placed upon them during workout sessions. Heat acclimatization guidelines mandate that athletes be introduced slowly to environmental stressors during practice sessions, resulting in lowering the risk for EHS.

By not mandating heat acclimatization guidelines, states are failing to protect their athletes, and in fact, are placing them at greater risk for EHS and other heat-related illnesses. Coaches, school leadership, parents and legislators must push their states to establish guidelines or have inadequate guidelines revised. The Korey Stringer Institute staff is readily available to assist with this process and when reviewing states polices we utilize the guidelines set forth by the National Athletic Trainers’ Association (NATA) in the consensus statement:

Casa DJ, Csillan D. Preseason heat-acclimatization guidelines for secondary school athletics. J Athl Train.2009;44(3):332–333.

Policies between the NCAA and high schools are very similar.  Review a Comparison of NCAA and High School HA Policies.

Heat Acclimatization

The Korey Stringer Institute suggests the following recommendations:

  1. Days 1–5 are the first formal practices. No more than 1 practice occurs per day.
  2. Total practice time should not exceed 3 hours in any 1 day.
  3. 1-hour maximum walk-through is permitted on days 1–5, however there must be a 3 hour minimum between practice and walk-through (or vice versa).
  4. During days 1–2 of first formal practices, a helmet should be the only protective equipment permitted (if applicable). During days 3–5, only helmets and shoulder pads should be worn. Beginning on day 6, all protective equipment may be worn and full contact may begin.
    1. Football only: on days 3–5, contact with blocking sleds and tackling dummies may be initiated.
    2. Full-contact sports: 100% live contact drills should begin no earlier than day 6.
  5. Day 6–14, double-practice days must be followed by a single-practice day. On single-practice days, 1 walk-through is permitted, separated from the practice by at least 3 hours of continuous rest. When a double-practice day is followed by a rest day, another double practice day is permitted after the rest day.
  6. On a double-practice day, neither practice day should exceed 3 hours in duration, and no more than 5 total hours of practice in the day. Warm-up, stretching, cool-down, walk-through, conditioning and weight-room activities are included as part of the practice time. The 2 practices should be separated by at least 3 continuous hours in a cool environment.
  7. Because the risk of exertional heat illnesses during the preseason heat-acclimatization period is high, we strongly recommend that an athletic trainer be on site before, during and after all practices.


The History of Adopting Heat Acclimatization Guidelines

In 2003 the NCAA began implementing heat acclimatization guidelines. Since the NCAA started these guidelines there has only been 1 death in collegiate football during the pre-season period, when there had been an average of 1-2 every pre-season (saving an projected 15 lives). In 2009 the NATA released guidelines very similar to those of the NCAA.  Since these have been released, KSI has been working with many state athletic associations (as well as others) to assist these states in the adoption of the guidelines for high schools as well as other sport levels. The table below reflects the timeline of those that have adopted these guidelines:


State/Entity Year Guidelines Were Adopted
NCAA 2003
New Jersey 2011
National Football League 2011
Texas 2011
North Carolina 2012
Georgia 2012
Arkansas 2012
Florida 2012
Arizona 2012
Connecticut 2013
Iowa 2013
Missouri 2013
Utah 2013
Mississippi 2013
Rhode Island 2013
Illinois 2013
Alabama 2014
Nebraska 2015
Hawaii 2016

In states that have passed and followed these heat acclimatization guidelines, there have been ZERO heat-related deaths in high school athletics.