Do Babies Need Extra Water During Heatwaves?

When temperatures rise, it’s natural for parents to worry about keeping their baby cool, comfortable and hydrated. During a heatwave, one of the most common questions new parents ask is:

“Does my baby need extra water?”

The answer depends largely on your baby’s age. While older babies may benefit from small amounts of water in very hot weather, younger babies usually get all the hydration they need from breast milk or formula alone.

Here’s what parents need to know about keeping babies safely hydrated during hot weather.

Babies Under 6 Months Usually Do Not Need Extra Water

For babies under six months old, breast milk or infant formula provides all the hydration they need — even during very hot weather.

Both breast milk and formula are mostly made up of water and are carefully balanced to meet a baby’s nutritional needs. Giving additional water to very young babies can sometimes be harmful because their kidneys are still developing.

Too much water can dilute the sodium levels in a baby’s body and interfere with feeding, as tiny stomachs fill up quickly.

Instead of offering water, focus on:

• Feeding more frequently
• Watching for signs of overheating
• Keeping your baby cool and comfortable

Breastfed babies may naturally want shorter, more frequent feeds during warm weather, which is completely normal.

Babies Over 6 Months May Have Small Amounts of Water

Once your baby starts solids, usually around six months, small amounts of cooled boiled water can be offered alongside their normal milk feeds.

During a heatwave, babies over six months may benefit from extra sips of water throughout the day, especially if:

• They’re eating solid foods
• They seem thirstier than usual
• They’re spending time outdoors
• The weather is particularly humid

Milk feeds should still remain their main source of hydration during the first year.

Signs Your Baby Might Be Too Hot or Dehydrated

Babies can become overheated more quickly than adults because they are less able to regulate their body temperature.

Signs your baby may be too hot include:

• Feeling hot to the touch
• Sweating
• Red or flushed cheeks
• Rapid breathing
• Restlessness or irritability
• Difficulty sleeping

Signs of dehydration can include:

• Fewer wet nappies
• Dark yellow urine
• Dry lips or mouth
• Sunken soft spot on the head
• Extreme sleepiness
• Crying without tears

If you’re concerned your baby may be dehydrated, seek medical advice promptly.

Simple Ways to Keep Babies Cool During a Heatwave

You don’t need complicated gadgets to help keep your baby comfortable in hot weather. Often, simple measures work best.

Dress Them Lightly

Choose lightweight, breathable fabrics such as cotton. In very hot weather, babies often need fewer layers than parents expect.

A nappy and lightweight vest may be enough indoors.

Keep Rooms Cool

During the day:

• Close curtains or blinds in sunny rooms
• Use fans to circulate air (not directly at your baby)
• Open windows when temperatures cool in the evening

Aim to keep sleeping areas comfortably cool where possible.

Avoid Direct Sunlight

Babies under six months should be kept out of direct sun as much as possible.

If you’re outside:

• Stay in the shade
• Use a parasol on the pram
• Dress your baby in a sun hat and light clothing

Never Cover a Pram or Pushchair With a Blanket

It might seem like a good way to create shade, but covering a pram or buggy with a blanket, muslin or cloth can actually make the temperature inside rise very quickly.

Even lightweight covers can trap heat and reduce airflow, creating an environment that becomes dangerously hot for babies during warm weather.

Instead:

• Use the pram’s built-in sunshade or canopy
• Attach a breathable parasol designed for pushchairs
• Check your baby regularly
• Keep air circulating around the buggy

If possible, avoid being outdoors during the hottest parts of the day, especially between late morning and mid-afternoon.

Offer Feeds More Often

Frequent feeding is one of the best ways to help babies stay hydrated during warm weather.

Don’t worry if feeding routines become less predictable during a heatwave — this is very common.

Can Babies Sleep in Just a Nappy?

Many parents wonder how to dress their baby for sleep during hot nights.

In very warm conditions, sleeping in just a nappy can be perfectly fine if the room temperature is high enough. Lightweight sleep bags with a low tog rating can also help.

As a rough guide:

• Below 20°C: lightweight sleepsuit and sleep bag
• 24°C and above: vest or just a nappy may be enough

Check your baby’s chest or back of neck to judge their temperature rather than hands or feet, which are often naturally cooler.

Trust Your Instincts

Heatwaves can make parents anxious, especially with a newborn, but most babies cope very well when kept cool, shaded and well-fed.

The key things to remember are:

• Babies under 6 months usually do not need extra water
• Frequent milk feeds are the best source of hydration
• Keep babies cool with light clothing and shade
• Never cover prams or pushchairs with blankets or muslins
• Watch for signs of overheating or dehydration

And remember — if you’re ever unsure or worried about your baby’s health, it’s always okay to contact your GP, health visitor or NHS 111 for advice.

At The Little Baby Brand, we know parenting comes with endless questions — especially during those first few months. Our goal is to help make everyday life with your little one feel just a little bit easier.