Heat Stroke Recognition

Look for these symptoms in athletes when exertional heat stroke (EHS) is suspected:

The two main criteria for diagnosing exertional heat stroke (EHS) are rectal temperature >105°F (40.5°C) immediately post collapse and central nervous system (CNS) dysfunction (e.g. irrational behavior, irritability, emotional instability, altered consciousness, collapse, coma, dizziness, etc.)

When observing athletes, look for other signs and symptoms that may indicate they are suffering from EHS:

  • Rectal temperature greater than 105°F (40.5°C).
  • Irrational behavior, irritability, emotional instability
  • Altered consciousness, coma
  • Disorientation or dizziness
  • Headache
  • Confusion or just look “out of it”
  • Nausea or vomiting
  • Diarrhea
  • Muscle cramps, loss of muscle function/balance, inability to walk
  • Collapse, staggering or sluggish feeling
  • Profuse sweating
  • Decreasing performance or weakness
  • Dehydration, dry mouth, thirst
  • Rapid pulse, low blood pressure, quick breathing
  • Other outside factors may include:
    • They are out of shape or obese
    • It is a hot and humid day
    • Practice is near the start of the season, and near the end of practice
    • It is the first day in full pads and equipment

If an athlete collapses during or immediately after exercise, consider EHS as a differential diagnosis. However, collapse is not required to consider EHS. Many athletes may display CNS dysfunction without collapse and healthcare professionals should still consider EHS as a differential diagnosis.


  • Heat exhaustion
  • Exertional hyponatremia
  • Concussion
  • Cardiac arrest

This page was last modified August 5, 2019