Every heatwave I get the same message, usually late in the evening, usually from somebody who is exhausted. My baby has fed all day. Should I be giving water?

The answer to the second question is no. The first is not a problem at all, it is your baby doing exactly the right thing.

Your baby is not feeding more because something is wrong

In hot weather a breastfed baby will feed far more often than usual, and each feed is often much shorter. They come on, take a few minutes, come off, and then want to go back on twenty minutes later. It can feel relentless, and it can feel like your milk has stopped being enough.

It has not. Your milk changes composition through a feed, and the milk at the start is thinner and higher in water. A baby who is thirsty rather than hungry takes a short drink and stops. That is why the pattern shifts to lots of little feeds. They are quenching their thirst, over and over, the same way you keep reaching for a glass of water on a hot day.

Yesterday I fed my own son twelve or thirteen times, and he is thirteen months old. That is not a baby with a feeding problem. That is a hot day.

A baby under six months does not need water

This is the important one, and it is worth being unambiguous about.

If your baby is under six months and fully breastfed, they need no water at all, however hot it is. Your milk provides every bit of the fluid they need. The NHS guidance is clear on this and it does not change in a heatwave.

There are two reasons it matters:

  • Water displaces milk. A small stomach filled with water is a stomach that cannot take a feed. Over a hot week that means fewer calories and it can affect weight gain.
  • It can upset the balance of salts in a young baby, whose kidneys are still immature.

From around six months, once your baby is having solid food, you can offer sips of cooled water from a cup alongside their feeds. Before that, the answer is simply more breastfeeding.

Formula-fed babies are different. They can be offered cooled boiled water between feeds in hot weather. Do not water down formula feeds, though, and never make bottles weaker than the instructions say.

Keeping your baby cool, and one thing not to do

Never cover a pram or buggy with a muslin or blanket

It is the advice that circulates every summer and it is genuinely dangerous. Even a thin cloth stops air moving through and turns the pram into an oven. Both the NHS and the Lullaby Trust warn against it, because overheating raises the risk of SIDS. Use a clip-on sunshade or parasol instead, and keep checking.

The rest is straightforward:

  • Dress them in very little. A nappy and a vest is plenty indoors on a hot day, and a nappy alone is fine.
  • Check their temperature properly, by feeling the back of the neck or the tummy. Hands and feet run cool and will mislead you.
  • Stay out of direct sun, and keep babies under six months out of it altogether. Go out early morning or evening rather than the middle of the day.
  • Keep the room cool. Curtains or blinds closed during the day, windows open when the air outside is cooler than in. A fan is fine in the room but should not blow directly onto your baby.
  • Fewer layers at night. A cooler room and a lighter sleeping bag. There is more on this in safe sleep.
  • A cool bath or a damp flannel on the back of the neck helps, and is a good way to settle a hot, cross baby before a feed.

Look after yourself too

Feeding through a heatwave is thirsty work and you will notice it.

Drink to thirst rather than forcing litres down. Keep a glass or bottle wherever you feed, because you will be pinned there for a lot of the day and you will forget otherwise. Eat something salty if you are sweating a lot.

You do not need to drink extra water to make more milk. Supply responds to milk being removed, not to how much you drink, and drinking beyond thirst does not increase it. Being genuinely dehydrated will make you feel dreadful, though, so it is worth staying on top of.

Skin to skin gets sticky in this weather. A thin muslin between you and your baby, or feeding somewhere with a fan moving the air, makes it bearable.

How to tell whether they are getting enough

Forget counting feeds. In hot weather the number goes up and tells you nothing. Count nappies instead.

From around day five you are looking for at least six heavy wet nappies in twenty four hours, with pale, mild-smelling urine. That does not change because it is hot. If your baby is still producing them, they are hydrated, however strange the feeding pattern looks.

There is more detail in is my baby getting enough milk.

Contact your midwife, health visitor or GP the same day if:

  • There are fewer than six heavy wet nappies in twenty four hours
  • Urine is dark or strong smelling, or there are orange or pink stains in the nappy after day three
  • Your baby is unusually sleepy or hard to rouse for feeds
  • Their mouth is dry, or they cry without tears
  • Your baby feels hot to the touch on the chest or back of the neck, or you think they have a temperature

Call 999 or take your baby straight to A&E if your baby:

  • Is floppy or unresponsive
  • Will not wake for feeds
  • Is having trouble breathing, or their lips, tongue or gums look blue or grey
  • Has a sunken fontanelle
  • Is visibly jaundiced and unwell with it, for example floppy, hard to wake or not feeding. Yellowing shows most clearly in the whites of the eyes, the gums, and the palms and soles
  • Has dark urine or pale, chalky stools

How a consultation helps

Most hot-weather feeding is exactly what it looks like, a baby drinking more often because they are thirsty, and the reassurance is the whole answer. But a heatwave is also a common point for feeding to unravel, because relentless feeding gets read as low supply, a top-up gets introduced, and a fortnight later supply really has dropped.

If you are not sure whether what you are seeing is the weather or a genuine problem, weighing your baby and watching a full feed settles it quickly. Far better to find out it is fine than to spend a hot week worrying about it on your own.