Low temperatures are increasing the risk of heart attacks and strokes for elderly people, smokers, and individuals with hypertension [1].
This trend is particularly critical during the May and June 2026 cold spell, as sudden temperature drops place significant stress on the cardiovascular system [4, 5].
Medical experts said the danger is most acute in southern Brazilian cities, including Curitiba, Porto Alegre, and São Paulo [3]. The physiological cause is vasoconstriction, which occurs when the body attempts to retain heat, subsequently raising blood pressure and stressing the heart [5].
Data regarding the exact increase in risk varies by source. The Instituto Nacional de Cardiologia said the cold can increase the incidence of heart attacks by up to 30% [2] and the occurrence of strokes by up to 20% [2]. However, other reports indicate a more severe impact, stating that intense cold can triple the risk of both heart attacks and strokes [1].
Health professionals have urged high-risk groups to take extra precautions. Doctors said that elderly and hypertensive patients must double their attention during this weather [1].
Reports from O Tempo said that the low temperatures recorded in late May and early June 2026 serve as a critical alert for cardiovascular health [3]. These periods of low temperature are typical for winter months but have prompted renewed warnings this year [4].
“Cold can increase the incidence of heart attacks by up to 30%”
The disparity in risk statistics—ranging from a 30% increase to a 300% increase—suggests that the level of danger is highly dependent on the severity of the cold and the pre-existing health status of the individual. For those with hypertension or advanced age, the physiological response to cold is not merely a discomfort but a significant medical trigger that can lead to acute cardiovascular events.
