Heat exhaustion
Heat exhaustion is one condition on the spectrum of raised body temperature derived from a heat illness. Other heat illnesses include heat cramps and heat stroke. Heat exhaustion is caused by the raising of a person's body temperature from either environmental conditions or by exertion. A raised internal body temperature can induce high amounts of perspiration out of the body, which can lead to the loss of water, salt and other electrolytes.[1][2]
Prevention of any heat-related illness includes avoiding exposure to very hot environments for prolonged periods, such as tropical sunshine in the middle of the day, or a boiler room, and drinking adequate fluids to replace insensible loss through perspiration, avoiding exertion and exercise in hot weather, avoiding medications that can be detrimental to the regulation of body heat, and removing or loosening clothing.[1][2][3]
Signs and symptoms
[edit]
U.S. National Weather Service resource[4]
Common signs and symptoms of heat exhaustion include:
- Elevated heart rate
- Lowered blood pressure
- Elevated core body temperature
- Excessive sweating
- Dehydration
- Loss of electrolytes
- Weakness
- Fatigue
- Persistent muscle cramps
- Skin tingling
- Nausea, vomiting
- Dizziness, light-headedness
- Irritability
- Headache[1][5][6]
Less common signs and symptoms of heat exhaustion include:
- Paling of the skin
- Hot and dry skin
- Syncope
- Central nervous system dysfunction (e.g., seizures, confusion, loss of spatial awareness, loss of bodily movement control, etc.)[1][5][6]
Common signs and symptoms of heat exhaustion can also be associated with other heat-related illnesses such as heat cramps, heat syncope, and heat stroke. Heat cramps, a mild form of heat-related illness, are exercise-associated muscle cramps caused by extreme physical exertion. While heat exhaustion has more systemic effects, the signs and symptoms of heat cramps are more localized to the abdominal, quadriceps, and calf muscles.[7] Heat syncope, a moderate form of heat-related illness, is also referred to as exercise-associated collapse. The symptom that differentiates heat syncope is decreased vasomotor tone, or decreased control of the contraction and relaxation of blood vessels.[7]
Heat exhaustion is a precursor to heat stroke, a more severe heat-related illness. Heat stroke shares common symptoms with heat exhaustion but is more likely to cause paling of the skin, hot and dry skin, syncope, and dysfunction of the central nervous system (e.g., seizures, confusion, loss of spatial awareness, loss of bodily movement control, etc.). One of the earliest indicators of heat stroke is confusion or altered mental status, which is the primary differentiator between heat exhaustion and heat stroke. Prompt recognition and treatment are crucial to prevent multi-organ failure and death.[8]
Causes
[edit]Common causes of heat exhaustion include:[9]
- Hot, sunny, humid weather
- Physical exertion, especially in hot, humid weather
- Due to impaired thermoregulation, elderly people and infants can get serious heat illness even at rest, if the weather outside is hot and humid, and they are not getting enough cool air.
- Some drugs, such as diuretics, antihistamines, beta-blockers, alcohol, MDMA ('Ecstasy', 'Molly'), and other amphetamines can cause an increase in the risk of heat exhaustion.[10]
Especially during physical exertion, risk factors for heat exhaustion include:[9]
- Wearing dark, padded, or insulated clothing; hats; and/or helmets (for example, football pads, turnout gear, etc.)
- Having a higher percentage of body fat
- Dehydration
- Fever
- Some medications, like beta blockers and antipsychotic medicines[10]
The body naturally responds to extreme temperatures by sweating to maintain thermoregulation and lower the body temperature. However, medications such as anticholinergics and antidepressants can affect an individual's sweat production, resulting in a decreased in sweating. For anticholinergic medications, this presents itself through adverse effects like dry mouth, which can lead to dehydration and increase an individual's risk of heat exhaustion. Other medications such as antidepressants and antihistamines with anticholinergic properties induces a similar effect, resulting in anticholinergic side effects and dehydration.[11]
Diagnosis
[edit]A diagnosis of heat exhaustion most commonly is diagnosed by medical professionals with various physical examinations. Through examination a person would have their temperature checked and questioned about their recent activity.[1] If the medical professionals suspect a person's heat exhaustion has progressed into heat stroke they may then lead with these varying tests to verify;
- Blood test, medical professionals when conducting a blood test look for low blood sugar or potassium. They may also look for the presence of unwanted gases in a person's blood.[1][2]
- Urinalysis, an urinalysis or urine test is a test to measure color, clarity, pH levels, glucose concentration, and protein levels.[12] The test additionally can check a person's kidney function, which is common to be affected by classic heat stroke.[2]
- Muscle function tests, medical professionals use muscle function tests to check for rhabdomyolysis. Which is severe damage to a persons skeletal muscle tissue.[13]
Treatment
[edit]First aid
[edit]First aid for heat exhaustion includes:[5][10]
- Moving the person to a cool place
- Having the person take off extra layers of clothes
- Cooling the person down by fanning them and/or putting wet towels on their body
- Having them lie down and put their feet up if they are feeling dizzy
- Having them drink water or sports drinks unless they are unconscious, too disoriented to drink, or vomiting
- Turning the person on their side if they are vomiting
Emergency medical treatment
[edit]If an individual with heat exhaustion receives medical treatment, Emergency Medical Technicians (EMTs), doctors, and/or nurses may also:[14]
- Provide supplemental oxygen
- Administer intravenous fluids and electrolytes if they are too confused to drink and/or are vomiting
Prognosis
[edit]When heat exhaustion is left untreated, the most common disease progression is heat stroke. According to the CDC, a typical trait indicating a person is having a heat stroke is when their body temperature reaches 106°F or higher in a span of 10 to 15 minutes.[15] In addition to a high body temperature, they will also experience central nervous system dysfunctions such as alteration in their mental status and rhabdomyolysis (injury to skeletal muscle). If a person is experiencing a heat stroke and is not properly treated, that can lead to metabolic abnormalities, irreversible damage, and death as a result.[16]
See also
[edit]References
[edit]- ^ a b c d e f "Heat Exhaustion: Symptoms & Treatment". Cleveland Clinic. Retrieved 2024-04-10.
- ^ a b c d Kenny, Glen P.; Wilson, Thad E.; Flouris, Andreas D.; Fujii, Naoto (2018). "Heat exhaustion". Handbook of Clinical Neurology. 157: 505–529. doi:10.1016/B978-0-444-64074-1.00031-8. ISSN 0072-9752. PMID 30459023.
- ^ Lipman, Grant S.; Eifling, Kurt P.; Ellis, Mark A.; Gaudio, Flavio G.; Otten, Edward M.; Grissom, Colin K. (December 2013). "Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Heat-Related Illness". Wilderness & Environmental Medicine. 24 (4): 351–361. doi:10.1016/j.wem.2013.07.004.
- ^ "Heat Cramps, Exhaustion, Stroke". National Weather Service. April 4, 2022. Retrieved June 26, 2024.
- ^ a b c Jacklitsch, Brenda L. (June 29, 2011). "Summer Heat Can Be Deadly for Outdoor Workers". NIOSH: Workplace Safety and Health. Medscape and NIOSH.
- ^ a b Bukhari, Hassan Adnan (2023-09-22). "A Systematic Review on Outcomes of Patients with Heatstroke and Heat Exhaustion". Open Access Emergency Medicine. 15: 343–354. doi:10.2147/OAEM.S419028. PMC 10522494. PMID 37771523.
{{cite journal}}: CS1 maint: PMC format (link) CS1 maint: unflagged free DOI (link) - ^ a b Gauer, Robert; Meyers, Bryce K. (2019-04-15). "Heat-Related Illnesses". American Family Physician. 99 (8): 482–489. ISSN 1532-0650. PMID 30990296.
- ^ Epstein, Yoram; Yanovich, Ran (2019-06-20). Longo, Dan L. (ed.). "Heatstroke". New England Journal of Medicine. 380 (25): 2449–2459. doi:10.1056/NEJMra1810762. ISSN 0028-4793.
- ^ a b "Heat Injury and Heat Exhaustion". www.orthoinfo.aaos.org. American Academy of Orthopedic Surgeons. July 2009. Retrieved January 1, 2016.
- ^ a b c "Heat Exhaustion and Heatstroke". www.nhs.uk. National Health Service of the United Kingdom. June 11, 2015. Retrieved January 1, 2016.
- ^ Cheshire, William P.; Fealey, Robert D. (2008-02-01). "Drug-Induced Hyperhidrosis and Hypohidrosis". Drug Safety. 31 (2): 109–126. doi:10.2165/00002018-200831020-00002. ISSN 1179-1942.
- ^ McPherson, Richard A.; Pincus, Matthew R. (2017-04-05). Henry's Clinical Diagnosis and Management by Laboratory Methods E-Book. Elsevier Health Sciences. ISBN 978-0-323-41315-2.
- ^ "What is Rhabdo? | NIOSH | CDC". www.cdc.gov. 2023-02-09. Retrieved 2024-04-10.
- ^ Mistovich, Joseph J.; Karren, Keith J.; Hafen, Brent (July 18, 2013). Prehospital Emergency Care (10 ed.). Prentice Hall. ISBN 978-0133369137.
- ^ "Heat Stress Related Illness | NIOSH | CDC". www.cdc.gov. 2023-10-27. Retrieved 2024-07-23.
- ^ Bukhari, Hassan Adnan (2023-09-22). "A Systematic Review on Outcomes of Patients with Heatstroke and Heat Exhaustion". Open Access Emergency Medicine. 15: 343–354. doi:10.2147/OAEM.S419028. PMC 10522494. PMID 37771523.
{{cite journal}}: CS1 maint: PMC format (link) CS1 maint: unflagged free DOI (link)