Heatwaves and the Expression of Psychiatric Disorders
Extreme heat transforms the city into a dense, almost motionless space where the air seems to hold both bodies and thoughts in suspension. During heatwaves, something shifts in the clinical landscape: familiar thresholds change, symptoms take on new contours, sometimes more sharply. Over the past weeks, I have observed in several patients a clear intensification of their difficulties - irritability rising more quickly, anxiety settling in more firmly, sleep unraveling, emotional fatigue appearing without warning. Heat acts as a subtle but persistent destabilizing factor, an external element that weakens internal regulatory processes.
Scientific literature describes this phenomenon with precision. Heatwaves are associated with increased psychiatric consultations and hospital admissions, particularly among individuals with psychotic disorders, mood disorders, or neurocognitive conditions. High temperatures disrupt thermoregulation, alter sleep, modify bodily perception, and impose an environmental stress that can amplify symptoms. Psychotropic medications contribute significantly to this vulnerability: certain antidepressants, neuroleptics, benzodiazepines, and lithium can reduce the body’s ability to cool itself, diminish thirst perception, or increase the risk of dehydration. Lithium levels, in particular, fluctuate with hydration and may reach toxic ranges during periods of intense heat. Research also notes an increase in suicidal risk, linked to emotional disorganization, impulsivity, and fragmented sleep.
In daily clinical practice, these findings take on a very concrete form. Patients living in overheated or isolated housing describe a sense of confinement, a loss of control, sometimes the reactivation of older anxieties. Those taking psychotropic medication report sensations of heaviness, mild confusion, diffuse discomfort. Heat seems to make the body less available, and the psyche follows. The disorders do not change in structure, but in intensity and in the way they manifest.
For practitioners, these periods demand particular attention. Heatwaves require integrating climate into clinical listening, recognizing that some symptoms do not reflect a worsening of the underlying disorder but rather a physiological and environmental context. They call for identifying patients whose treatments or living conditions expose them more strongly, reinforcing preventive guidance, adapting consultation conditions, and maintaining close coordination with physicians when treatments require increased monitoring. Heat reminds us that psychic life is never isolated from the world: it is shaped by seasons, bodies, places, and material constraints. It invites us to consider clinical work as a living space, sensitive to the variations of reality.
References (APA)
Berry, H. L., Bowen, K., & Kjellstrom, T. (2010). Climate change and mental health: A causal pathways framework. International Journal of Public Health, 55(2), 123–132.
Hansen, A., Bi, P., Nitschke, M., Ryan, P., Pisaniello, D., & Tucker, G. (2008). The effect of heat waves on mental health in a temperate Australian city. Environmental Health Perspectives, 116(10), 1369–1375.
Page, L. A., Hajat, S., & Kovats, R. S. (2012). Relationship between daily suicide counts and temperature in England and Wales. British Journal of Psychiatry, 200(5), 466–471.
Stöllberger, C., & Finsterer, J. (2007). Heat-related side-effects of psychotropic drugs. European Journal of Clinical Pharmacology, 63(9), 877–884.
