Extreme Heat


Extreme Heat; More Than An Annoyance
Risks for Psychiatric Population

– Robin Cooper, MD

Extreme heat is more than an annoyance; it is responsible for the largest mortality due to weather events followed by tornadoes and hurricanes. (Bobb, 2014) There are severe health and mental health risks of extreme heat.

Mentally ill patients have been reported to die at twice the rate of non-psychiatric population during extreme heat. ( Bark, 1998) There are greater number of emergency room visits and hospitalizations during heat waves for patients with pre-exiting mental illness . (Wang, et al, 2014, Hansen, et al, 2008). Suicide rates have reported to be increased during extreme heat waves:  (Page, 2007)

Psychiatric medications can impair the body’s normal heat regulatory functioning and pose a risk to psychiatric patients.  (Matin-Latry, European Psychiatry, 2007).

People with schizophrenia are particularly vulnerable to heat. They exhibit impaired thermo-regulatory functioning, which diminish their ability to compensate to heat stress, which may be intrinsic to the disease itself.  (Chong, 2004)

Extreme heat is correlated with increase of aggression with one standard deviation increase in temperature leading to 4% increase in interpersonal violence and 14% increase in-group violence.  (Burke, M, Hsiang, S., et al, 2015). This presents particular risks for domestic abuse for children and women. There is speculation that serotonin depletion during increased heat may be one of the factors contributing to violence.  (Carlton, 2016)

Extreme heat has impact on cognitive functioning with marginally functioning individuals at greatest risk.  (Hancock, et al. 2003)

Increased nighttime temperatures impair sleep. Impaired sleep and insomnia has broad effects including impaired concentration, irritability, impatience and aggravate all psychiatric difficulties. (Obradovich, et al. 2017)


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Burke, M, Hsiang, SM, Miguel, E.  Climate and Conflict.  Annual Review of Economics. Vol. 7:577-617, 2015, Aug.

Chong, TW, Castle DJ.  Layer upon layer: thermoregulation in Schizophrenia.  Schizophr Res 2004, Aug 1 ; 69 (2-3): 149-57

Hancock, PA, Vasmatzidis, I: Effects of heat stress on cognitive performance: the current state of knowledge. International Journal of Hyperthermia. Vol 19, 2003- Issue 3: 355-372

Hansen, A., Peng B, Nitschke M, et al.  The Effect of Heat Waves on Mental Health in Temperate Australian City.  Environ HealthPerspect; vol 116; 2008, Oct.

Martin-Latry K, Goumy MP, Latry P, Gabinski C, Begaud B, Faure I, Verdoux H.  Psychotropic Drugs use and risk of heat-related hospitalisations.Eur Psychiatry. 2007 Sept; 22(6): 335-8.

Obradovich, N, Migliorini, R, Mednick, SC, Fowler, JH.  Nightime temperature and human sleep loss in a changing climate.  Sciences Advances. Vol 3, no.5. 26, May 2017.

Page LA, Hajat S, Kovats RS. Relationship between daily suicide counts and temperate in England and Wales.  Br. J. Psychiatry: 2007 Aug: 191: 106-12

Wang X, Lavigne E, Ouellette-kuntz H, Chen BE.  Acute impacts of extreme temperature exposure on emergency room admissions related to mental and behavior disorders in Toronto, Canada.  J Affect Disord. 2014 Feb; 155: 154-61