Dr. José Massa, psychiatrist and vice president of Medical Affairs at APS Health, warned Monday at a press conference that extreme heat poses particular dangers to psychiatric patients, since some medications alter sweating and body temperature regulation.
Massa said antipsychotics and tricyclic antidepressants can impair the sweat glands through anticholinergic effects, meaning patients treated for schizophrenia, bipolar disorder, or dementia may not realize they can't sweat normally. He also flagged risks from lithium, which is eliminated mainly through the kidneys, warning that inadequate hydration can push the drug to toxic levels.
Warning signs include confusion, altered consciousness, nausea, and vomiting; Massa stressed that confusion in these patients should not automatically be attributed to their mental health condition, since it may instead signal heat-related dehydration, and urged people to seek immediate medical care or call emergency services if it occurs. He cited data from Puerto Rico's Syndromic Surveillance System showing 740 emergency room visits related to heat during 2025 and so far in 2026, based on reports from 15% of hospitals in Puerto Rico, plus 240 heat-related health problems reported so far this year.