Why Heatwaves Are Harder on Women's Bodies Than Men's
From hormonal shifts to socioeconomic factors, women face unique risks during extreme heat. Here's what experts want you to know.
Why Heatwaves Hit Women Harder — And What Needs to Change
As record-breaking temperatures continue to batter the UK, health experts are sounding the alarm on a lesser-known truth: extreme heat does not affect everyone equally. Women, in particular, face a distinct and often underestimated set of risks when heatwaves strike — and specialists say it's time for greater awareness and targeted protective measures.
The Biology Behind the Vulnerability
According to Dr. Nighat Arif, an NHS GP specialising in women's health, heatwaves act as a serious "stress-test" for the female cardiovascular system. Two core biological factors are at play: hormonal fluctuations and the way women's bodies physically respond to heat.
Research, including a 2025 study, confirms that women produce less sweat and only begin perspiring at higher temperatures compared to men. This means the body is slower to shed excess heat — and because less visible sweat appears on the skin or clothing, women may not even realise how much physical strain they're under.
Additionally, women tend to have a higher core body temperature and a greater percentage of body fat, which acts as an insulating layer, trapping heat rather than releasing it. When this is combined with the natural hormonal fluctuations tied to the menstrual cycle, perimenopause, menopause, pregnancy, and breastfeeding, the brain's temperature regulation system can be thrown significantly off balance.
Beyond Biology: Social and Economic Factors Also Play a Role
Dr. Cat Pinho-Gomes, an academic public health consultant at UCL's Institute for Global Health and co-author of a major review on sex differences in heatwave-related deaths, emphasises that the risks aren't purely biological.
Socioeconomic circumstances — including lower average wages and the disproportionate caregiving responsibilities many women carry — can limit a woman's ability to properly protect herself during extreme heat. Women may find it harder to rest, stay hydrated, or access cooler environments when they are the primary caregiver for children or elderly relatives.
Age is another compounding factor. Because women live longer on average than men, they are more likely to be among the elderly population most vulnerable to heat-related illness. Older individuals also face higher rates of dementia, which can impair the ability to recognise thirst, and may rely on diuretic medications for blood pressure management — both of which increase exposure to heat stress.
Women may also be marginally more likely than men to die from heatwave-related causes, though researchers note that more data is needed to draw firm conclusions.
How the Menstrual Cycle Intensifies Heat Stress
For women who menstruate, extreme heat can collide painfully with their monthly cycle. During the second half of the cycle, rising progesterone levels push core body temperature even higher. Then, when a period begins, oestrogen — the hormone that drives the body's thermoregulatory system — drops to its lowest point, placing additional strain on the heart as it works to cool the body down.
Women who experienced a heatwave while menstruating have described severe fatigue, dizziness, fainting episodes, intense brain fog, and overwhelming exhaustion — symptoms that go well beyond typical period discomfort.
Menstruation also leads to iron loss, which is particularly significant for women with heavy periods. Low iron compromises the body's ability to deliver oxygen efficiently, adding yet more demand on an already overworked cardiovascular system.
Perimenopause, Menopause, and the Heat Connection
For perimenopausal and menopausal women, falling oestrogen levels already trigger hot flushes and night sweats under normal conditions. During a heatwave, these episodes can become more frequent and far more intense — a reality that is expected to worsen as global temperatures rise, according to research on the impact of climate change on menopause.
Women who have been placed in a chemical or surgical menopause — a treatment used for hormone-sensitive cancers and conditions such as endometriosis — face the same challenges.
One woman described her hot flushes during a recent heatwave as "truly horrendous, especially at night time" — a sentiment echoed by many others navigating menopause in increasingly extreme summer temperatures.
A Call for Targeted Action
The overarching message from health professionals is clear: heatwave safety guidance needs to better reflect the specific vulnerabilities women face. Generic heat advice is not enough. From period management strategies to menopause support and broader access to cool environments, a more tailored and gender-informed approach to heat health is urgently needed — especially as climate change makes extreme summers the new normal.
