Why are babies more vulnerable to heat?
Unlike adults, infants cannot signal when they are thirsty or spontaneously adjust their behavior in response to heat. Their thermoregulatory system is still underdeveloped, which exposes them to two main risks: dehydration and heatstroke.
Both of these conditions can develop quickly, even inside a poorly ventilated home. Caution is advised as soon as temperatures exceed 25°C.
Hydrating your baby: best practices by age
Hydration is the first line of defense. Needs vary depending on feeding method:
- Breastfed baby (0–4 months): breast milk naturally adapts to your child’s water needs. Offer the breast as often as your baby asks, or even more frequently in hot weather. No additional water is needed. Also remember to stay well-hydrated yourself.
- Bottle-fed babies (0–4 months): continue with the usual bottle feedings. You can offer small amounts of cooled boiled water between feedings. Do not change the proportions of the formula.
- Babies on solid foods (4–6 months and older): Offer water regularly, at least every hour in hot weather. Choose fruits and vegetables high in water content: watermelon, cantaloupe, strawberries, cucumber, and tomatoes. Yogurt also helps with hydration.
Tap water is perfectly fine, unless there are local health warnings. Avoid fruit juices, nectars, and sodas.
How can you recognize the warning signs?
There are a few signs you should watch for. If your baby shows any of these symptoms, act quickly:
- Less frequent urination, darker urine, or urine with a strong odor
- Dry mouth, sunken eyes
- Unusual drowsiness or, conversely, restlessness
- Hot, dry skin; fever over 38°C
- Nausea, vomiting
If your baby shows signs of heatstroke—such as a high body temperature, flushed skin, lack of sweating, or confusion—immediately move them to the shade or a cool place, undress them, cool them down with a damp cloth, and call 144right away.
Protect your baby from the sun and heat every day
Protection starts even before you go out:
- Avoid going out between 11 a.m. and 4 p.m., when UV radiation is at its strongest.
- Outdoors: light, covering clothing, a wide-brimmed hat, SPF 50+ sunscreen on exposed areas (for babies 6 months and older; for younger babies, prioritize shade and clothing). Reapply sunscreen every two hours and after each swim. Don’t forget sunglasses!
- In a stroller: attach a sunshade. Never cover the carrycot with a sheet or blanket: the temperature inside rises very quickly.
- In the car: never leave your baby alone in a vehicle, even for a few minutes. The temperature can rise by 10°C in ten minutes.
- At home: keep shutters and curtains closed during the day; air out the room in the evening and early in the morning. A room thermometer is useful; aim for 20–22°C at night. Lukewarm baths (34–35°C) and a mist sprayer help gently cool your baby.
When should you see a doctor?
Seek medical attention immediately if your baby has a fever over 38°C, is vomiting, has diarrhea, or if their urine becomes infrequent and very dark. These signs may indicate dehydration requiring medical care, especially in infants under 6 months.
Key points
- Babies dehydrate quickly and cannot express their thirst: offer fluids regularly, without waiting for signs.
- Sun protection starts with shade, clothing, and a hat—sunscreen is used as a supplement starting at 6 months.
- Avoid going out during the hottest hours of the day (11 a.m.–4 p.m.) and never leave your baby alone in a car.
- Dark urine, a dry mouth, or unusual drowsiness should be cause for concern and prompt a quick visit to the doctor.
- If you suspect heatstroke, cool your baby down immediately and call 144.