Heatwaves Raise Medication Risks and Mental Health Hospitalizations

Prolonged extreme heat can complicate the effects of several medicines, raising the risk of dehydration or heat‑related illness. Health officials advise patients to stay well‑hydrated, monitor symptoms and consult their physicians before altering treatment during heatwaves.

A large international study analysing more than 2.6 million hospital admissions in Brazil, Canada, Chile and New Zealand between 2000 and 2019 found that periods of at least four consecutive days with temperatures above the 97.5th percentile were linked to a 5.6 % rise in admissions for mental‑health and behavioural disorders. The increase was strongest among older adults, residents of low‑density areas and those on medications that affect heat tolerance. Researchers say health systems should anticipate higher demand for psychiatric care during prolonged heat events.