Welcome back to Just Curious, Strong Women’s weekly series exploring all the random health and fitness questions you’ve always wondered about but never got the answers to.

This week, we’re exploring the common causes of heat rash or prickly heat and how to prevent it as the temperatures rise.

The start of June has been and gone, which means summer is finally here and we can look forward to some balmy temperatures over the coming months.

For many people, hot weather is a welcome occurrence – a chance to sit back in a pub garden with your mates and enjoy a pint or two. But for those who struggle with heat rash, the rising mercury means only one thing: the return of redness.

What is it about the hot weather that causes this rash? Why are some people more affected than others? And is there anything you can do to prevent or treat it? We asked Dr Kajal Babamiri, a dermatologist at CLNQ, to explain. 

Heat rash is caused by more than your skin just getting a bit hot – it occurs when the sweat ducts on the surface of your skin get clogged and sweat cannot escape.

Also known as prickly heat or miliaria, the symptoms of heat rash are caused by inflammation and irritation because of this clog or blockage, which is why it can cause angry red spots and itching or prickling on the surface of the skin.

“Heat rash is most common in hot, humid conditions,” Dr Babamiri explains. “It often affects areas of the body where skin folds or clothing can cause friction, such as the neck, armpits and groin.” 

Other factors that can contribute to heat rash include excessive sweating – either due to a medical condition or exercising in a hot environment – tight clothing, prolonged exposure to heat and humidity and poor ventilation of the skin.

Children are particularly susceptible to heat rash because their sweat glands are not fully developed, which is why many adults ‘grow out of’ the condition as they mature. 

The main symptoms of heat rash are:

• Small, raised spots (on white skin these spots will appear red, but on darker skin they can be harder to see and appear as white or grey)
• An itchy, prickly feeling
• Mild swelling of the skin 

Your susceptibility to heat rash will depend on many factors. Put simply, those who sweat more are more likely to develop heat rash, no matter the cause.

That means people who tend to sweat excessively (hyperhidrosis), those with antidepressant-induced excessive sweating (ADIES) and people who are not acclimatised to hot climates (like holidaymakers) are at higher risk.

Exercising in the heat can also make developing a rash more likely, as your body will sweat more than usual to help keep you cool. 

“People with underlying skin conditions such as eczema or those who wear occlusive clothing that doesn’t allow the skin to breathe may experience heat rash more frequently,” Dr Babamiri says.

“Age can also play a role – children and elderly individuals may be more vulnerable due to their skin’s sensitivity and reduced ability to regulate temperature.” 

Because heat rash is caused by excessive sweating and skin moistness, the best thing you can do to prevent heat rash is keep your skin cool and dry.

“Wearing loose, breathable clothing made from natural fibres like cotton can help to reduce sweating and allow air to circulate around the skin,” Dr Babamiri says. “Staying in cool, shaded areas and using fans or air conditioning to lower ambient temperatures can also prevent overheating.”

If you want to exercise outside (and who wouldn’t when it’s so glorious), then taking precautions to keep yourself cool is also key.

Carrying a small, microfibre towel will allow you to mop away excess sweat (although leaving some sweat will help keep you cool) and bringing cold drinks and wet towels is a great way to avoid overheating. Exercising during the hottest hours of the day is discouraged.

“Regularly bathing and keeping the skin clean and dry is also essential, as is using lightweight bedding and avoiding heavy blankets in hot weather,” Dr Babamiri adds. “For those prone to heat rash, applying talcum powder or corn starch to areas where sweating is heavy can help absorb some moisture.” 

If you sweat a lot or are especially prone to heat rash, you’ll want to have some tools under your belt to deal with any flare-ups.

To start with, you’ll want to make sure that you keep the area cool and dry to avoid any further heat rash developing, so make sure to stay out of the heat where possible.

You can also use a topical treatment to reduce discomfort and soothe the rash. “Over-the-counter creams and lotions, such as calamine lotion or hydrocortisone cream, can alleviate itching and reduce inflammation,” Dr Babamiri explains. “In more severe cases, a healthcare provider may prescribe topical or oral antibiotics if there is a risk of infection.”

Taking many of the prevention steps outlined above, such as wearing loose, breathable clothing and taking cool baths and showers can help to ease symptoms.

In most cases, the heat rash will resolve on its own with the help of these steps. If symptoms persist or become worse even after you keep the area cool and dry, pay your GP a visit. They can advise you on the next steps. 

Images: Getty