As the UK continues to experience warmer and more humid summers, particularly with frequent heatwaves, heat rash, a once seemingly tropical condition, has become more common. Also known by its medical term miliaria, heat rash is now affecting increasing numbers of people across the country. It’s uncomfortable, irritating, and sometimes even painful. But thankfully, it’s usually preventable and treatable with simple measures.
What Is Heat Rash?
Heat rash happens when the body’s sweat glands become blocked, trapping sweat beneath the skin. This blockage leads to inflammation, resulting in small red bumps, clear blisters, or an intense prickling sensation. Although it’s most common in hot and humid climates, the condition has been on the rise in the UK during periods of high temperature and moisture, especially in areas where airflow is limited, such as under clothing or in skin folds.
There are different types of heat rash, ranging from the mildest form, miliaria crystallina, which produces clear, tiny blisters, to miliaria rubra, also known as prickly heat, which causes red, itchy, and inflamed spots. More severe types like miliaria profunda or miliaria pustulosa involve deeper layers of skin or infection, but these are less common and usually occur after prolonged or repeated exposure to hot, sweaty environments.
What Causes Heat Rash?
At its core, heat rash is caused by the blockage of sweat ducts. In conditions where the body produces more sweat than usual, such as during exercise, fever, or hot weather, the sweat cannot escape properly. Dead skin cells, thick lotions, or tight clothing can worsen the blockage. When sweat is trapped, it irritates the skin and leads to inflammation.
Though anyone can develop heat rash, some groups are more susceptible than others. Infants, for example, are especially prone to it because their sweat ducts are not yet fully developed. Adults wearing non-breathable clothing, people who stay in bed for extended periods, and those with conditions that impair temperature regulation are also more vulnerable.
In the UK, even moderate heat can trigger the condition, especially when it’s accompanied by high humidity and poor ventilation. Anecdotal evidence from online forums and public health advisories reveals that many UK residents experience outbreaks of heat rash during heatwaves, particularly those working outdoors or commuting on crowded public transport.
Symptoms
The most common symptom of heat rash is a patch of small red spots or clear fluid-filled bumps. These typically appear on the neck, chest, back, groin, under the breasts, or in the folds of the arms and legs. The rash often causes a prickling or stinging sensation, giving rise to its nickname “prickly heat”.
In some cases, the skin may feel warm or itchy, and scratching can lead to secondary infection, further complicating the condition. For people with more severe forms of miliaria, the skin may become swollen or tender or develop pustules, which are signs that the area may be infected and needs medical attention.
Heat Rash in the UK is a Growing Issue
Although official statistics are limited, NHS advice and public health updates suggest that heat rash has become a more frequent concern in recent UK summers. According to NHS Wales and the Met Office, more people are reporting heat-related symptoms, including heat rash, as summer temperatures climb. With parts of the UK recently hitting highs of 30°C and beyond, the risk of heat-related skin issues like miliaria has significantly increased.
The condition may be underreported, as many people manage it at home without seeking medical help. Nonetheless, pharmacies and online health services like Livi have noticed a spike in consultations for skin rashes, itching, and inflammation during warmer months, which further hints at the growing prevalence of heat rash in Britain.
Treatment
In most cases, heat rash is mild and clears up within a few days without medical treatment. The key to managing it is cooling the skin and avoiding further sweat build-up. Cool showers, air conditioning, fans, and loose-fitting cotton clothing can all help. It’s best to avoid heavy creams, oily lotions, and synthetic fabrics, as they can worsen the blockage of sweat glands.
Over-the-counter treatments are also effective. Calamine lotion soothes itching, while gentle moisturisers like E45 can help relieve dry or irritated skin. For more stubborn or severe rashes, mild corticosteroid creams (like hydrocortisone 1%) may be used, though these should be applied cautiously, especially on sensitive areas like the face. Antihistamines can help reduce itching, and antiseptic washes can prevent bacterial infection if scratching has broken the skin.
Some pharmacies also recommend medicated powders, often containing menthol or antibacterial agents, which help absorb sweat and keep the skin dry. In infants, barrier creams or gentle talc alternatives may be used to prevent or ease symptoms.
Recent improvements in skincare and medical advice have made treatment easier and more accessible. The focus has shifted towards preventative skincare, with new non-perfumed products designed specifically for sensitive or heat-prone skin. Additionally, greater public awareness, helped by weather alerts and NHS campaigns, has empowered people to act quickly and prevent flare-ups before they escalate.
How do you prevent Heat Rash
Prevention is often simpler than cure. Staying cool and dry is the best way to avoid heat rash. This means choosing breathable clothing made of cotton or linen and avoiding prolonged sun exposure during peak hours (typically between 11 a.m. and 3 p.m.). Also, staying hydrated throughout the day helps to stay safe.
For those who are bedridden or confined to hot spaces, frequent cooling with damp cloths, gentle fans, and regular changes of bedding or clothing can be helpful. Using fragrance-free soaps and moisturisers can prevent skin irritation, while talc-free body powders help absorb moisture in vulnerable areas.
Parents of young children and babies should pay extra attention to keeping their children’s skin cool and dry. Infants should be dressed in light layers, and nappies should be changed frequently to prevent sweat build-up. For adults, it’s also wise to avoid intense physical activity during very hot days unless proper cooling measures are in place.
Finally,
While heat rash is often dismissed as a minor nuisance, it can become a serious source of discomfort, especially if left unmanaged during periods of high heat. In the UK, where rising temperatures and humidity are becoming more common, awareness of heat rash is essential. Fortunately, with proper skincare, timely treatment, and simple preventative steps, it’s possible to stay cool, comfortable, and free of rashes throughout the summer. As the NHS and other health bodies continue to issue heat-related health advice, staying informed about heat rash and other seasonal conditions is becoming a basic part of public health literacy.