The year 2024 marked the first time that the global average temperature exceeded the 1.5 C threshold set by the Paris Agreement. One direct consequence is more intense heat extremes, which already pose a significant threat to human health.

By 2080, the city of Montréal, for example, could experience between 37 and 54 days per year with temperatures exceeding 30 C compared to only 11 between 1976 and 2005.

Older adults are considered most vulnerable to heat. During the exceptionally hot European summers of 2022, 2023 and 2024, approximately 84 per cent of the 181,446 deaths attributed to heat occurred among adults aged 75 and older. The pattern was similar during the 2021 heat dome in western Canada.

It’s urgent to thoroughly investigate the reasons why seniors are more susceptible to extreme heat, especially considering population aging, like in provinces like Québec where one in four people will be over 65 by 2031. We also need to discover whether this vulnerability can be alleviated.

This article is part of our ongoing series The Grey Revolution. The Conversation Canada and La Conversation are exploring the impact of the aging boomer generation on Canadian society, including housing, working, culture, nutrition, travelling and health care. The series explores the upheavals already underway and those looming ahead.

Why older bodies struggle with heat

The health effects of heat stem primarily from excessive heat buildup in the body. Compared to young adults, older adults generally experience a more pronounced........

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