Heat exhaustion or exercise-associated collapse is a type of heat-illness that is less severe than heat stroke. It typically occurs after an athlete completed an event or practice.
Heat exhaustion after activity is believed to be due to postural hypotension. This is a condition where the blood pressure drops due to the pooling of blood in the limbs instead of flowing back to the heart. During activity, the repeated strong contractions of the working muscles function as a second pump which forces the blood back to the heart. Once the individual stops activity, the efficiency of the venous return is diminished.
Indications of heat exhaustion
- Muscle cramping
- Nausea or vomiting
- Excessive sweating
If the condition is left untreated and the individual is left in high temperatures, heat exhaustion can progress to heat stroke which is a serious condition. Progression to heat stroke occurs if the following are present:
- Rectal temperature that rises to 41 degrees C
- Elevated heart rate up to 100 beats per minute
- Systolic blood pressure drops below 100 mm Hg
- Position the individual on his/her back with the legs elevated
- Provide a sports beverage
- It is expected for improvement to show within 10 minutes and the individual might be able to stand and walk within 30 minutes.
- If the heart rate stays elevated and the blood pressure does not rise, intravenous fluids are given.
Disclaimer / More Information
The information posted on this page on heat exhaustion is for learning and educational purposes only. To learn to properly provide first aid for heat exhaustion, register for first aid training at one of our training centers located throughout Canada. The training centers are in Edmonton, Calgary, Vancouver, Kelowna, Surrey, Winnipeg, Toronto, Ottawa and Halifax.