What is heat rash?
If your little one suddenly develops a bright red pimply rash on their neck, under their arms, or near the edges of their diaper or underwear, don't panic; it's most likely just a heat rash. Heat rash, also known as 'miliaria', is a red, pimply skin rash that can appear when your child overheats in hot and humid weather. You may also see heat rash in the winter if they've been sweating under many layers of clothing.
Advertisement | page continues below
The rash most likely appears in folds of the skin and on parts of the body where clothing fits snugly, including the upper chest, neck, groin and armpits
(Levin 2009). If your child wears hats, the rash may even spread across their scalp or forehead.
Is heat rash serious?
It's isn't, but it is a sign your child is too warm. Take steps to cool them off, like moving them into the shade, or into a cool room, and removing some layers of clothing. In very rare cases, severe heat rash can progress to more serious conditions, like heat exhaustion or heat stroke.
If this happens, your child will be unable to control their body temperature, his body temperature may become much higher than normal and this can lead them to be dehydrated (NHS 2008).
What causes heat rash?
When it's hot and humid outside, your child sweats to cool down, just as we adults do. Some babies and older children have skin pores that clog easily – when this happens, the sweat can’t get out, and heat rash develops.
Tight or heavy clothing can trap the sweat as well, contributing to the irritation. A child can get heat rash from anything that causes them to sweat heavily, such as a high temperature or from racing around in a hot environment
(Levin 2009).
Is heat rash painful for my child?
No, it isn't usually painful, but it can be annoyingly itchy, and the intense prickling or stinging sensation may be distressing for your child. Some of the pimples may also be tender to the touch.
How should I treat heat rash?
Most heat rashes will clear up in a few hours or even days time but, in the mean time, there are several things you can do to relieve your child's itching and discomfort:
- Avoid hot and humid environments. Move into an airy room or a shady spot and if your child is racing around, encourage some quiet time to reduce the amount of sweating. Try using a fan if you're out and about in the summer heat. If the weather stays hot at night, place a fan near your child's bed.
- Take off their clothes or dress them in cotton. Avoid synthetic fabrics, such as polyester and nylon, that trap heat; opt for natural fibres instead. Where possible loosen or remove their clothing and give them as much diaper-free time as you can.
- Keep their skin cool. Cool the affected areas directly using cold, wet cloths, or give your baby a lukewarm bath or shower. Let the air dry their skin as much as possible instead of using towels; a little more nude time can help heal the rash.
- Use hydrocortisone cream on the advice of your doctor or pharmacist if the rash is very severe.
Advertisement | page continues below
Avoid ointments and other lotions since they can make the rash worse by trapping moisture in the skin.
Check with your doctor if your child has a high temperature. They may recommend giving them infant acetaminophen to ease any discomfort and lower their temperature. (Never give aspirin to a young child as, in rare cases, it may cause a life-threatening condition known as Reye's syndrome.)
Keep an eye on your child during this time: as their temperature drops, they could get chilly and need to be warmed up again.
How can I prevent heat rash?
Keep your child comfortably cool by dressing them in loose, light, cotton clothing, particularly in warm weather.
Advertisement | page continues below
If you aren't sure whether they're overheated, touch their skin. Damp hot skin is a sign they're too warm. On a hot day, keep your child inside or look for cool, shady or breezy places to sit and play outside. Make sure your child drinks plenty of fluids to prevent dehydration.
Should I take my child to the doctor for heat rash?
See your doctor if:
- your child has a high temperature (over 39 degrees C)
- your child has signs of dehydration. For example they're not drinking well and not peeing as often as usual
- the rash doesn't go away after three or four days
- the rash appears to be getting worse
