Heat Stroke

by Jai Sappal

Exercise this time of year can be a little uncomfortable – surely its time the humidity was turned down just a little right?? Staying active when it is hot comes with its own set of unique challenges. Some of the big ones are remaining hydrated and helping your body to adequately and effectively dissipate the heat produced during exercise. If we are unable to do this we might be at risk of heat stroke.

What is Heat Stroke?
Heat stroke appears to be misused on social media and in sport when talking about athletes looking dehydrated or sweating heaps. Notable moments are during the Australian Open when the commentators would use the phrase heat stroke when describing the way the athletes appeared. If heat stroke were present in these tennis superstars, you would hopefully have emergency medical services attending the player. Heat stroke is a medical emergency! There are a spectrum of heat related illnesses; on the less severe end of the scale we have heat cramps, followed by heat exhaustion, and finally heat stroke.

These conditions are caused by an inability by the body to regulate its temperature. Other causes can stem from dehydration and alcohol consumption (1). Unchecked heat exhaustion can lead to heat stroke.

Importance of Sweat
Our bodies have an in-house feature to cool down during hot moments – Sweating! Sweating is a very effective way for the body to regulate its temperature. This is done by some water and salt loss through the pores in your skin, where the water will evaporate and cool the skin. Without the ability to sweat, our body would not be able to control its internal heat effectively and we would likely just die! (4). Sweating is important. It’s good for you but also dependent on the activity being done.

Heat Cramps vs Heat Exhaustion vs Heat Stroke
(Taken directly from: https://www.health.qld.gov.au/news-events/news/difference-between-heat-exhaustion-and-heatstroke-dehydration-heatwave)

Heat Cramps


  • Muscle pains and spasms, usually in the abdomen, arms or legs
  • Most common in people who sweat a lot during strenuous activity

What to do:

  • Stop all strenuous activity
  • Rest in a cool, shaded place
  • Increase fluid intake with water, low sugar sports drink or diluted fruit juice
  • After the cramps subside, wait a few hours before exercising strenuously
  • Seek medical attention if cramps continue for more than one hour

Heat Exhaustion


  • Heavy sweating
  • Heat cramps
  • Paleness
  • Weak or dizzy
  • Nausea or vomiting
  • Fast, weak pulse
  • Headache

What to do:

  • Rest in a cool, shaded place
  • Have a cool shower or bath, or apply cool, wet towels to the body
  • Loosen tight clothing
  • If fully alert, sip water or suck ice chips
  • Seek medical attention immediately if symptoms are severe, get worse or don’t improve with treatment, or last longer than an hour

Heat Stroke


As per heat exhaustion, plus:

  • Worsening mental condition
  • Slurred speech, poor coordination
  • Seizures or losing consciousness
  • May even have dry skin/no sweating (2)

What to do:

  • Call Triple Zero (000) immediately – this is a life-threatening emergency
  • Follow directions of ambulance staff
  • Move to a cool, shaded place
  • Remove excess clothing
  • Immerse in water, spray with hose, or apply wet cloths and fan vigorously

So… Australia can be pretty hot, especially during February. What are some ways you can continue to move without overheating? Firstly, make the most of evenings and mornings and secondly, maximise the effectiveness of your in house cooling system. Sweat works via evaporative cooling – the more movement of air against your skin the more effective it is, so take it outside, or set yourself up in front of a fan. Pay attention to your heart rate, if you are exercising in a heat stress condition, your heart rate, or the feeling of exertion (how hard you are working) will likely be higher than it usually is – use this as a warning and lower the intensity a little. We would love to hear from you if you have any other strategies you have used for continuing to stay active on those really hot weeks!


  1. https://www.healthline.com/health/heat-stroke-vs-heat-exhaustion#causes
  2. https://www.beaumont.org/health-wellness/blogs/know-the-difference-between-heat-stroke-heat-exhaustion
  3. https://www.health.qld.gov.au/news-events/news/difference-between-heat-exhaustion-and-heatstroke-dehydration-heatwave
  4. https://www.canr.msu.edu/news/is-sweating-good-for-you


Jai Sappal
Peak Health Services.