Overview
Summer has finally arrived. But in recent years, the joy and the thought of warm and cozy days filled with outdoor activities that we all longed for appear to have dissipated. Instead, we have been swamped with warnings of potential heat waves due to climate change. Experts in climate science have predicted that in the coming decades, there will be an increase in the duration, frequency, and intensity of heat waves during the summer months across the globe. During such months, heat-related illnesses are one of the major challenges faced by public health officials. In the summer of 2022, there were more than 45,000 heat-related mortalities in Europe (Nature Medicine paper). Similarly, heat-related illnesses have also taken a toll in the U.S with more than 2,300 deaths reported in 2023 (US Dept of Health and Human Services).
Heat exhaustion, a heat-related illness, occurs when one’s body temperature rises above normal and the body fails to cool down. This happens when a person is engaged in physical activity on a hot and humid day. Intense physical activity results in sweating. Sweat assists in maintaining body temperature by cooling one’s skin through evaporation. However, on a humid day, the rate of sweat evaporation drops and the body cannot cool down. Sweating causes loss of water and salts from one’s body. If one does not replace the loss of water by drinking water or other liquid, the person concerned will become dehydrated and this can lead to heat exhaustion. If left untreated, heat exhaustion can lead to heatstroke with serious implications as it is life threatening.
Risk factors for heat exhaustion
A number of factors have been identified as risk factors for heat exhaustion:
Age. Elderly people (especially those over 65 years of age) and young children (mainly those under four years of age) are more prone to heat exhaustion as their body temperature cannot be easily regulated.
Alcohol consumption. Drinking alcohol results in dehydration which in turn elevates the risk of heat exhaustion.
Physical activity. Participating in physical activity or working on a hot and humid day increases the risk of experiencing heat exhaustion. Women, Caucasians, and individuals who were raised in temperate zones are more likely to be affected by heat exhaustion.
Symptoms of heat exhaustion
Prior to displaying symptoms of heat exhaustion, a person may experience heat rash or heat cramps. Heat cramps are muscle cramps affecting mainly the muscles on one’s arms or legs but other muscles can also be affected. The following are symptoms of heat exhaustion:
· Faintness
· Tiredness
· Fever
· Vomiting and nausea
· Heavy sweating and cool, damp skin
· Rapid heartbeat, weakness, and low blood pressure
· Headache
· Dehydration
· Diarrhea
Diagnosis
Healthcare professionals usually obtain one’s rectal temperature and make inquiries about one’s recent activities. One is only required to undergo blood, urine, and muscle function tests as well as undergo X-rays if one is suspected to developed heatstroke following heat exhaustion.
Management and treatment
Once a person has been diagnosed with heat exhaustion, it is imperative to take action. The person affected should:
· Drink cool liquids. One should only drink water or sports drinks that contain salt and sugar to replace the salts that were lost through sweat. One should avoid alcoholic or caffeinated beverages as these fluids can cause more dehydration.
· Take off thick, tight-fitting or excess clothing. Replace these clothes with nonbinding ones.
· Rest in a cool place. Do not engage in any physical activity. Search for a shady spot or sit in front of a fan or rest in an air-conditioned room. Lie down and raise one’s feet about 12 inches.
· Take a cool shower. One can also place a wet towel soaked in cold water on one’s forehead or the back of one’s neck to help reduce one’s body temperature.
· Obtain help if one’s condition does not improve after an hour’s rest and drinks. One should contact one’s physician or call 911 or go directly to the emergency department of a hospital.
References
Ballester J, Quijal-Zamorano M, Méndez Turrubiates RF, Pegenaute F, Herrmann FR, Robine JM, Basagaña X, Tonne C, Antó JM, Achebak H. Heat-related mortality in Europe during the summer of 2022. Nat Med. 2023 Jul;29(7):1857-1866. doi: 10.1038/s41591-023-02419-z. Epub 2023 Jul 10. Erratum in: Nat Med. 2024 Feb;30(2):603. doi: 10.1038/s41591-023-02649-1. Assessed and Endorsed by the MedReport Medical Review Board