Older people, children, and people on certain medications may be at greater risk too.

I’m sure you’ve noticed, but it bears repeating: phwoar, it’s hot out at the minute, isn’t it? 

Temperatures are expected to reach 40C in some places in the coming week, the Met Office has warned. 

Speaking on ITV’s Lorraine, GP and author Dr Amir Khan said some of us may experience the heat differently to others. 

“Women struggle in the heat more than men, and it’s all to do with biology,” he said on the daytime show.

Dr Amir said women generally sweat less than men, which does seem to be the case – though that may be because women are smaller on average.

Women’s sweat glands tend to be more densely-packed than men’s, and even though we excrete less actual moisture, we use a higher percentage of those glands.

Still, a 2010 paper found that typically, women need to get hotter than men do in order to break a sweat, and that our perspiration is usually less efficient.

That matters because sweat is one of the main ways in which the body cools itself down.

Your menstrual cycle can also make life more difficult in a heatwave. 

“If you’re a menstruating woman, the second half of your menstrual cycle where your progesterone levels are high can increase your temperature by up to half a degree,” the doctor continued. 

Indeed a paper found that the luteal phase of a person’s cycle (after ovulation) might increase women’s core temperature by 0.3°C to 0.7°C.

Menopause, meanwhile, can create hot flushes, Dr Amir continued. These can be extra brutal in the heatwave.

And lastly, the GP said, another mechanism our bodies rely on to cool us down – bringing blood up to the surface of our skin so the heat can evaporate, a process called vasodilation – is not as “efficient” a system in women due to smaller heart chambers and smaller blood vessels.

“And after the menopause, when oestrogen levels drop... [blood vessels] don’t dilate as well,” he added.

Some research has shown that women’s hearts are more affected by heat stress, and it does seem to be true that postmenopausal women’s vasodilation is less effective (though exercise seems to reduce that risk).

Of course, women aren’t the only people that may be disproportionately affected by a heatwave. 

Per the NHS, other people at greater risk include: 

Babies and young children aged five and under,

People with underlying health conditions, particularly heart problems, breathing problems, dementia, diabetes, kidney disease, Parkinson’s disease or mobility problems,

People on certain medications (e.g. antidepressants and antipsychotics),

People with serious mental health problems,

People who are already ill and dehydrated, for example from diarrhoea and vomiting,

People who experience alcohol or drug dependence,

People who are physically active and spend considerable time outside, such as runners, cyclists and walkers,

People who work in jobs requiring manual labour or extensive time outdoors,

People experiencing homelessness, including rough sleepers and those who cannot control the temperature of where they live,

People who live alone and may be unable to care for themselves.

Dr Paula Cowan, the regional medical director for primary care at NHS England in the North West, said: “Older people, babies, and young children are more vulnerable because their bodies are less able to regulate temperature, and people with underlying health conditions can also be significantly affected.”

No matter who you are, she added: “We advise people to keep out of the sun during the hottest part of the day, between 11am and 3pm. If you are planning any physical activity – such as exercising or walking the dog – try to do this in the cooler morning or evening hours. Make sure you drink plenty of fluids, apply sunscreen, and wear a hat when you are out.”