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:[1][5][6]
- 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
Less common signs and symptoms of heat exhaustion include:[1][5][6]
- Paling of the skin
- Hot and dry skin
- Syncope
- Central nervous system dysfunction (e.g., altered mental status, loss of spatial awareness, loss of bodily movement control, seizures, etc.)
Common signs and symptoms of heat exhaustion can also be observed in other heat-related illnesses such as heat cramps, heat syncope, and heat stroke. Heat cramps, a mild form of heat-related illness, is characterized by persistent abdominal, quadricipital, and calf muscle contractions. These muscle contractions occur due to an imbalance of electrolytes, including sodium, potassium, and calcium, resulting from excessive sweating during intense physical exertion in high temperatures.[7] Heat syncope, also referred to as exercise-associated collapse, is a moderate form of heat-related illness. It is characterized by a temporary loss of consciousness due to insufficient blood flow to the brain. This impairment in blood flow occurs because the blood vessels in the skin are dilated to increase blood flow to the skin's surface. This vasodilation allows for more heat to be transferred from the blood to the environment via radiation, convection, and evaporation to help lower the core body temperature. However, this process also lowers the blood pressure and therefore blood flow to the brain. Unlike heat exhaustion, heat cramps and heat syncope do not have systemic effects.[7]
Heat exhaustion is a precursor to heat stroke, a 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., altered mental status, loss of spatial awareness, loss of bodily movement control, seizures, etc.). One of the earliest indicators of heat stroke is altered mental status, which can manifest as delirium, confusion, reduced alertness, loss of consciousness, etc. Central nervous system dysfunction is the primary differentiator between heat exhaustion and heat stroke. Prompt recognition and treatment are crucial to prevent multi-organ failure and death.[1][5][6][8]
Causes
[edit]As global temperatures continue to rise, there continues to be an increase in data that links hotter temperatures to diseases, disorders, and mortality rates. According to The Intergovernmental Panel on Climate Change (IPCC), temperatures are predicted to increase by up to 1.5°C in the future due to actions such as continued greenhouse gas emissions.[9] Some common causes of heat exhaustion and other heat related illnesses include:[10]
- Hot, sunny, or humid weather
- Physical exertion through work or exercise
- Dehydration
Risk Factors
[edit]Risk factors for heat exhaustion include:[10]
- Wearing dark, padded, or insulated clothing; hats; and/or helmets (for example, football pads, turnout gear, etc.)
- Having a higher percentage of body fat
- Fever
- Due to impaired thermoregulation, children younger than four years old and adults older than 65[11] are at a higher risk for serious heat illness even at rest if the weather outside is hot and humid, and they are not getting enough cool air.
- Some medications, such as diuretics, antihistamines, beta-blockers, antipsychotics, MDMA ('Ecstasy', 'Molly'), and other amphetamines, to name a few can cause an increase risk for heat exhaustion.[12]
Medication
[edit]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. Similarly, other medications, such as antidepressants and antihistamines with anticholinergic properties, induce comparable effects, causing anticholinergic side effects and dehydration.[13]
Prevention
[edit]Ways to prevent and lower risk of heat exhaustion include:[14][15]
- More public widespread announcement of heat waves or rapid increases in temperature
- Staying up to date on daily weather reports
- Providing more heat shelters throughout communities
- Wearing more loose fitting and and lighter fabric clothing
- Try to stay well hydrated unless fluid intake is limited
- For those who are doing more extraneous activities or work, find shady cool areas to rest
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.[16] 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.[17]
Treatment
[edit]First aid
[edit]First aid for heat exhaustion or heat stroke includes:[5][18]
- Moving the person to a shaded, fanned, or air-conditioned place
- Removing any excess or tight clothing to facilitate cooling
- Applying wet towels or ice packs wrapped in cloth to the forehead, neck, armpits, and groin, and using a fan to cool the person down
- Lying the person down on their back and elevating their feet above head level to improve blood circulation
- Having the person drink cool water or sports drinks, also referred to as electrolyte drinks, provided they are conscious, alert, and not vomiting (Only applies to heat exhaustion)[19]
- Turning the person on their side if they are vomiting to prevent choking
- Monitoring the person's vital signs, which includes their heart rate, blood pressure, breathing rate, and body temperature
- Monitoring the person's mental status (i.e., confusion, delirium, reduced alertness etc.)
- Contacting emergency medical services
- Transporting or having emergency medical services transport the person to an emergency department if their situation does not improve quickly
Emergency medical treatment
[edit]If an individual with heat exhaustion receives medical treatment, Emergency Medical Technicians (EMTs), doctors, and/or nurses may also:[20]
- Provide supplemental oxygen
- Administer intravenous fluids and electrolytes if they are too confused to drink and/or are vomiting
Do Not
[edit]If an individual is experiencing heat exhaustion or any other heat related illness DO NOT:[21]
- Administer fever medications such as aspirin or Tylenol as they can be harmful for the individual
- Administer salt tablets as they can worsen dehydration[22]
- Use alcohol or caffeine containing products as they can make it harder for the individual to control their body temperature
- Give anything by mouth if the person is vomiting or unconscious
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.[23] In addition to a high body temperature, they will also experience central nervous system dysfunctions such as alteration in their mental status and slurred speech. Another possible illness that heat stroke can lead to is rhabdomyolysis or rapid injury to skeletal muscle especially when heat stroke is caused by physical exertion.[24] If a person is experiencing a heat stroke and is not properly treated, that can further progress to metabolic abnormalities, irreversible damage to multiple organs in the body, and death as a result.[6]
See also
[edit]References
[edit]- ^ a b c d e f g "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". Thermoregulation: From Basic Neuroscience to Clinical Neurology, Part II. Handbook of Clinical Neurology. Vol. 157. pp. 505–529. doi:10.1016/B978-0-444-64074-1.00031-8. ISBN 978-0-444-64074-1. 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. PMID 24140191.
- ^ "Heat Cramps, Exhaustion, Stroke". National Weather Service. April 4, 2022. Retrieved June 26, 2024.
- ^ a b c d Jacklitsch, Brenda L. (June 29, 2011). "Summer Heat Can Be Deadly for Outdoor Workers". NIOSH: Workplace Safety and Health. Medscape and NIOSH.
- ^ a b c d 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.
- ^ 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. PMID 31216400.
- ^ Faurie, Clare; Varghese, Blesson M.; Liu, Jingwen; Bi, Peng (2022-12-15). "Association between high temperature and heatwaves with heat-related illnesses: A systematic review and meta-analysis". Science of the Total Environment. 852: 158332. Bibcode:2022ScTEn.85258332F. doi:10.1016/j.scitotenv.2022.158332. ISSN 0048-9697. PMID 36041616.
- ^ a b "Heat Injury and Heat Exhaustion". www.orthoinfo.aaos.org. American Academy of Orthopedic Surgeons. July 2009. Retrieved January 1, 2016.
- ^ Ansorge, Rick; Painter, Kim. "Heat Exhaustion: Symptoms and Treatment". WebMD. Retrieved 2024-07-24.
- ^ Layton, J. Bradley; Li, Wenhong; Yuan, Jiacan; Gilman, Joshua P.; Horton, Daniel B.; Setoguchi, Soko (2020-12-10). "Heatwaves, medications, and heat-related hospitalization in older Medicare beneficiaries with chronic conditions". PLOS ONE. 15 (12): e0243665. Bibcode:2020PLoSO..1543665L. doi:10.1371/journal.pone.0243665. ISSN 1932-6203. PMC 7728169. PMID 33301532.
- ^ 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. PMID 18217788.
- ^ Glazer, James L. (2005-06-01). "Management of Heatstroke and Heat Exhaustion". American Family Physician. 71 (11): 2133–2140. PMID 15952443.
- ^ CDC (2024-05-15). "Preventing Heat-Related Illness". Extreme Heat. Retrieved 2024-07-25.
- ^ 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.
- ^ "Heat Exhaustion and Heatstroke". www.nhs.uk. National Health Service of the United Kingdom. June 11, 2015. Retrieved January 1, 2016.
- ^ US Department of Commerce, NOAA. "Heat Cramps, Exhaustion, Stroke". www.weather.gov. Retrieved 2024-07-25.
- ^ Mistovich, Joseph J.; Karren, Keith J.; Hafen, Brent (July 18, 2013). Prehospital Emergency Care (10 ed.). Prentice Hall. ISBN 978-0133369137.
- ^ "Heat emergencies Information | Mount Sinai - New York". Mount Sinai Health System. Retrieved 2024-07-24.
- ^ "Keeping Workers Hydrated and Cool Despite the Heat | Blogs | CDC". 2011-08-12. Retrieved 2024-07-24.
- ^ "Heat Stress Related Illness | NIOSH | CDC". www.cdc.gov. 2023-10-27. Retrieved 2024-07-23.
- ^ Kruijt, Nick; van den Bersselaar, L. R.; Hopman, M. T. E.; Snoeck, M. M. J.; van Rijswick, M.; Wiggers, T. G. H.; Jungbluth, H.; Bongers, C. C. W. G.; Voermans, N. C. (2023-05-19). "Exertional Heat Stroke and Rhabdomyolysis: A Medical Record Review and Patient Perspective on Management and Long-Term Symptoms". Sports Medicine - Open. 9 (1): 33. doi:10.1186/s40798-023-00570-y. ISSN 2199-1170. PMC 10199157. PMID 37204519.