What is it?
Heat illness occurs when the body loses its ability to prevent overheating. Normally the body removes excess heat via four different ways.
1. Evaporation: sweating
2. Convection: heat transferred to the environment by motion such as air or water
3. Conduction: transfer of heat from one object to another via direct contact
4. Radiation: transfer from one object to another without direct contact
Heat illness is a spectrum that ranges from mild (heat cramps) to moderate (heat exhaustion) with the most severe being heat stroke.
What are the Symptoms?
Early signs and symptoms include swelling of the hands and feet, cramps, muscle tightening, muscle spasms, and lightheadedness.
More severe signs and symptoms include confusion, agitation, irritability, lack of coordination, headache, nausea, vomiting, excessive sweating, flushing of skin, and rectal temperature greater than 104º F.
What are the Risk Factors?
• Age: More common in older adults and children
• Exercising in the heat especially if not acclimated
• Sudden change in environmental temperature
• Heavy clothing and/or sporting equipment
• Humid weather
What Is the Treatment?
Those with mild symptoms should be treated with fluids and resting in a cool area. Those with more severe signs and symptoms may require whole body immersion for cooling and transfer to the nearest hospital. Never delay cooling of anyone suspected of having a heat illness.
How Can It Be Prevented?
Athletes should acclimate their body to heat and humidity at least 10 days prior to competition. During this process the body adapts by lowering the core temperature, decreasing resting heart rate, increasing sweat rates, and increasing storage of water within the body.
It is also important to wear light colored and lightweight clothing while exercising. Activity should also be planned around weather conditions, such as avoiding exercise during the peak temperatures of the day. Everyone should hydrate before, during, and after any activity. The best guide to hydration is thirst. If you are taking medications and/or supplements review these with your physician prior to starting any exercise regimen.
When Can I Return to Play?
If you have a heat-related illness you should be evaluated by a physician prior to returning to exercise. Once you are cleared to return by your doctor you should begin your exercise in a cool environment with gradually increased activity.
Written by, Dr. Derek Worley