Heat rash, sunburn and mosquito protection for babies in an Indian summer

Babies cope with heat less well than adults, so an Indian summer needs some planning. Most heat rash settles once the skin is kept cool. Shade and light clothing protect young babies better than sunscreen, and a net protects them better than smoke from a coil. Here are the questions parents ask Dr Dutta most in the hot months, with short answers.

What is prickly heat (heat rash) in babies?

Prickly heat is a rash of tiny raised spots caused by sweat trapped under the skin. It is uncomfortable but usually harmless.¹

When a baby sweats a lot, the tiny sweat ducts get blocked and the trapped sweat irritates the skin. Babies get it often because they control their body temperature less well than older children.¹

The spots are about 2 to 4 mm across, may contain clear fluid, and feel itchy or prickly. On brown skin they can look grey or white rather than red.¹ They are common on the neck, chest, back, armpits and nappy area. Heat rash is not infectious.¹

How do I treat prickly heat in my baby?

Cool the skin and stop the sweating. Most heat rash then fades on its own within a few days.¹

• Dress your baby in loose cotton clothing.¹ At home in the hottest hours, a nappy alone is fine.
• Give a lukewarm bath or sponge with plain water.
• Pat the rash rather than rubbing or scratching.¹
• Avoid perfumed soaps and creams.¹
• Calamine lotion can ease the itch.¹

Avoid thick oils, heavy creams and talcum powder in summer. Oil massage in the heat can block sweat ducts further, and powder can be breathed in. Do not use steroid creams on a baby without a doctor's advice. Even mild hydrocortisone is not advised for children under 10 without a doctor.¹

See a doctor if the rash does not get better after a few days.¹ Also see a doctor if spots fill with pus or your baby has a fever, as this may be an infection.

How can I keep my baby cool without AC?

Keep your baby in the coolest room, out of direct sun, with moving air from a fan and light cotton clothing.

• During the day, close curtains, and keep windows shut if it is hotter outside than inside.² Open them in the cooler evening.
• Keep out of the sun between 11am and 3pm.²
• Use a ceiling or table fan, not pointed straight at the baby from close up.
• Give a lukewarm sponge bath, or lay a damp cotton cloth near (not on) your sleeping baby.
• Avoid synthetic sheets, thick mattresses with plastic covers, and heavy blankets.
• Never leave a baby in a parked car, even for a few minutes.

Feel your baby's tummy or the back of the neck, not the hands and feet, to judge whether they are too hot. A sweaty, flushed baby with damp hair needs fewer clothes.

Is it safe to use a fan for a baby in summer?

Yes. A fan is safe and helpful, and may even lower the risk of sudden infant death.

In a study from California, babies who slept with a fan on had a 72% lower risk of SIDS (sudden infant death syndrome) than those who did not. The link was stronger in warm rooms.³ This kind of study shows a link, not proof, but there is no reason to avoid a fan.

Keep the fan out of reach, use a safe speed, and still put your baby to sleep on the back, on a firm flat surface.

Does my breastfed baby need water in hot weather?

No. A baby under 6 months who is exclusively breastfed does not need extra water, even in very hot weather.

A study in a tropical summer measured exclusively breastfed babies aged 1 to 4 months on summer days when room temperatures reached 34 to 41 degrees C. Babies given only breast milk stayed just as well hydrated as babies given extra water. Those given water drank less breast milk.⁴

In the heat, offer the breast more often, and drink more water yourself. Formula-fed babies should have their formula made up correctly, never diluted, and you can ask your doctor about small amounts of boiled cooled water.

How should I dress my baby in hot weather?

Use a single layer of loose, light-coloured cotton. Light, loose clothing helps the body lose heat.²

At home in the afternoon, a nappy and a thin cotton vest is often enough. Outdoors, cover arms and legs with loose cotton and add a wide-brimmed cotton hat, which protects from both sun and mosquitoes. Paediatricians in the USA suggest light, cool clothes that cover as much skin as practical.⁵

Avoid tight swaddling, woollen caps and socks in summer. Grandmothers often worry that babies "catch cold" without layers. In Kolkata in May, overheating is the bigger risk.

What are the signs of heat exhaustion and heat stroke in a child?

Heat exhaustion causes tiredness, headache, heavy sweating, pale clammy skin, thirst, irritability, cramps and sometimes vomiting.² Heat stroke is more serious: a very high temperature, hot skin that has stopped sweating, fast breathing, confusion, fits or fainting.²

Infants are among the people most vulnerable to heat.⁶ In babies, look for unusual drowsiness or irritability, refusing feeds, fewer wet nappies, a sunken soft spot, and hot, dry skin.

Heat stroke is a medical emergency.²

What should I do if my child has heat exhaustion or heat stroke?

Move your child somewhere cool, take off extra clothes, give fluids, and cool the skin with water and a fan. A child with heat exhaustion should feel better within 30 minutes.²

• Give water or ORS to drink.² Only give drinks if your child is alert enough to swallow safely.
• Sponge or spray the skin with cool water and fan it. Cold packs wrapped in cloth can go under the armpits or on the neck.²
• For a baby, keep breastfeeding.

Go to hospital immediately if your child is not better after 30 minutes, or has any sign of heat stroke.² On the way, wrap them in a cool wet sheet or keep sponging and fanning.²

Can babies use sunscreen?

For babies under 6 months, shade and clothing come first. Sunscreen is used only on small areas such as the face when shade and clothes are not possible.⁵

The American Academy of Pediatrics advises keeping babies under 6 months out of direct sunlight, under a tree, umbrella or pram hood.⁵

For older babies and children, use a broad-spectrum sunscreen with SPF 15 or more (up to SPF 50). Reapply every 2 hours, and after sweating or swimming.⁵ Test a little on the inner arm first, and choose a fragrance-free product.

Too much sun in childhood matters later: sun exposure early in life raises the risk of skin cancer.⁷

Do babies need sun exposure for vitamin D?

Babies do not need to be put in direct sun for vitamin D. A daily vitamin D supplement of 400 IU prevents rickets in infants.⁷

Many families in India lay the baby in the sun after an oil massage. In winter mornings, a few minutes of gentle sun on a covered baby is pleasant. But in summer, direct sun on a young baby risks sunburn, heat rash and overheating. Ask your paediatrician about vitamin D drops instead.

How do I treat sunburn in a child?

Move your child out of the sun, cool the skin with lukewarm water or damp cloths, and give plenty of fluids. Mild sunburn usually heals within a few days.

• Apply a plain, fragrance-free moisturiser or aloe vera gel.
• Paracetamol in the right dose for weight can ease pain.
• Do not pop blisters, and do not apply ice, toothpaste or ghee.
• Keep the burnt skin covered and out of the sun until it heals.

See a doctor if a baby under 1 year gets sunburnt, or if a child has blisters over a large area, fever, chills, vomiting, or seems drowsy. These can be signs of heat illness as well.

Which mosquito repellents are safe for babies?

For young babies, a mosquito net is the safest protection. For older babies and children, repellents containing DEET or picaridin are safe when used as the label directs.^8,9

Parents of newborns and premature babies are advised to be especially careful about putting DEET or other chemicals on the skin.⁸ Netting over prams and baby carriers works well.⁸

• Higher DEET strengths last longer: 10% DEET protects for about 2 hours and 30% for about 5.⁸
• Picaridin 5% protects for 3 to 4 hours, and 20% for 8 to 12 hours.⁸
• Do not use oil of lemon eucalyptus in children under 3 years.⁸
• Do not put repellent on children's hands, which go into the mouth and eyes. Spray it on your own hands and then rub it on the child's face.⁸
• Avoid combined sunscreen and repellent products.⁸
• Wash it off with soap and water when back indoors.⁸

Most serious problems with DEET in children have come from accidental overdoses or misuse that ignored label warnings.⁹ Wristbands soaked in repellent are not proven to work.⁸

Are mosquito coils and vaporisers safe to use in a baby's room?

Dr Dutta advises against burning mosquito coils in a closed room with a baby. Coil smoke contains very fine particles and chemicals that can harm the lungs.

A study that tested common coil brands from Asia found that burning one coil could release as much fine particle pollution as 75 to 137 cigarettes. The smoke also contained formaldehyde and other chemicals linked to cancer.¹⁰

Plug-in liquid vaporisers do not make smoke, but they still release insecticide into the room air. If you use one, keep the room ventilated, switch it on before the baby sleeps, and keep it well away from the cot. A net over the cot or bed is safer than any of these.

What is the best way to protect my baby from mosquito bites?

A well-tucked mosquito net over the bed or cot, at night and during day naps, is the best protection for babies.

The mosquitoes that spread dengue bite during the day.¹¹ WHO advises clothes that cover the body, nets for daytime sleep, window screens and repellents containing DEET, picaridin or IR3535.¹¹ In malaria areas, insecticide-treated nets reduced deaths in children from all causes by 17% and cut malaria episodes by about half.¹²

Stop mosquitoes breeding near your home: empty, cover and clean water containers, and clear rubbish that holds rainwater.¹¹ Check flower vases, coolers, flower pot trays and the roof after Kolkata monsoon showers.

When should I take my baby to a doctor in hot weather?

Go to hospital immediately if your child has:²

• a very high temperature with hot, dry skin
• confusion, unusual drowsiness, a fit or fainting
• fast breathing or a fast heartbeat
• heat exhaustion that is not better after 30 minutes of cooling and fluids

See a doctor the same day if your baby:

• is feeding poorly, or has far fewer wet nappies than usual
• has fever in the monsoon with rash, vomiting, tummy pain or bleeding gums, which can be dengue
• has heat rash with pus, spreading redness or fever
• has blistering sunburn, or is under 1 year with any sunburn

A baby under 3 months with a temperature of 38 degrees C or more needs urgent care: go to hospital now, day or night.