Each extra heat-wave day tracked with higher stroke odds in a São Paulo patient series, and the link was stronger with PM10

What the research found

Medical Xpress posted this on 29 October 2026. These are preliminary findings presented by Alessandra Carvalho Goulart of the University of São Paulo Faculty of Medicine at FAPESP Week Netherlands. This is a conference briefing. The English sources used here do not give a journal DOI. Contemporaneous accounts of the same talk describe the EMMA cohort, which is FAPESP-funded: 769 people with acute stroke seen from 2006 to 2018, of whom 65.5 percent were 65 or older and 54.2 percent were women. A heat wave was at least two consecutive days with a maximum of at least 33.1 degrees Celsius (92 degrees Fahrenheit). In a heat-only model, the odds ratio was 1.121 per additional heat-wave day. A continuous interaction of heat with PM10 had an odds ratio of 1.404, described as 40.4 percent higher odds per additional day of that combination. Those counts and odds ratios are attributed to accounts of that same preliminary talk. This card does not add a dehydration or blood-thickness explanation, because that wording was not in the primary account used here. The series includes both women and men, so it is not tagged as a women-only result. It is specific to São Paulo patients with stroke. It does not show that one hot day causes a stroke in an individual. Not medical advice.

Evidence level: Human study. A study in people, but an association isn't proof of cause.

Read the original at Medical Xpress