Coping with hot weather in pregnancy

Hot weather can be extra challenging when you’re pregnant. With hot weather and heatwaves becoming more common, Tommy’s midwife Amina has some tips for staying safe and well in hot weather, at home and abroad.

It’s normal to feel warmer and sweatier than usual when you’re pregnant. This is due to changes in hormones and blood flow and can affect you at all stages of pregnancy. In later pregnancy, carrying your bump around can make you feel hot and bothered too.  

In early pregnancy it can be hard to tell the difference between new symptoms related to your pregnancy and the effects of hot weather.

Tiredness, feeling warm, feeling lightheaded or dehydrated can all be the effects of pregnancy.  In a heatwave there’s more risk of dehydration, fainting, heat exhaustion and heatstroke. Here are some things to watch out for and some simple things you can do to stay well in the heat. 

Stay hydrated

Drinking enough can help you stay well, especially in hot weather, and can help reduce tiredness and constipation. Try to drink about 1.6 litres a day, or 6 to 8 medium (200ml) glasses. In hot weather you’re likely to need more. Having a bottle or glass of water nearby and taking frequent sips can help you get enough to drink.  

All fluids count, not just water, but it’s best to limit drinks containing caffeine, as they can affect your baby, and to avoid having lots of sugary drinks.

When you don’t drink enough or  you have pregnancy sickness, then you may get dehydrated, particularly in hot weather. This is when your body loses more fluid than it is taking in. Keep an eye out for symptoms of dehydration and if worried seek medical advice from your GP, NHS 111 or an early pregnancy unit if you are under their care. 

Signs of dehydration

If you have any of these, you may be dehydrated:

  • feeling thirsty
  • wee that is dark yellow or strong-smelling
  • feeling dizzy or lightheaded  
  • feeling tired  
  • having a dry mouth, lips and eyes
  • not weeing very often, fewer than 4 times a day.  

Keep cool

It’s a good idea to seek the shade if you’re outside and avoid being out in the sun in the hottest part of the day (between 11am and 3pm). If you do go out in the sun, use sunscreen and wear a hat.  

Wearing loose clothes made of natural fabrics like cotton, taking a cool shower or bath, eating cold foods and sprinkling water over your skin can all help you stay cool. Keeping windows and curtains or blinds closed during the day and opening windows at night can help keep your house cool. Using an electric fan may help, if the temperature is below 35 degrees.

Watch out for signs of heat exhaustion and heat stroke.  Signs of heat exhaustion include tiredness, dizziness, feeling sick, being very thirsty and fast breathing or heart rate. Moving to a cool place, taking off clothes you don’t need, cooling your skin with water or cold packs should all help.  

If you’re still unwell after half an hour of trying to cool down, you might have heat stroke, which is a medical emergency. You can find out the symptoms of heat stroke from this NHS page. 

Swollen hands and feet

Swelling in your legs, ankles, feet and fingers is common in pregnancy, as your body hangs on to water. This can be worse in hot weather. Things you can do to help include not standing for long periods, wearing comfortable shoes, resting with your feet up (above your hips) as much as you can, and drinking plenty of water.

Sudden swelling can be a sign of pre-eclampsia, a serious condition that needs immediate treatment. You should call your midwife or hospital maternity unit immediately if you have:  

Giving birth in a heatwave? 

Find out more about keeping cool during labour.

Sources

NHS. Common health problems in pregnancy. https://www.nhs.uk/pregnancy/related-conditions/common-symptoms/common-health-problems (Page last reviewed: 22/04/2024. Next review due: 22/04/2027)

NHS. Dehydration https://www.nhs.uk/conditions/dehydration (Page last reviewed: 14/11/2022. Next review due: 14/11/2025)

NHS. Heat exhaustion and heat stroke https://www.nhs.uk/conditions/heat-exhaustion-heatstroke  (Page last reviewed: 12/08/2022. Next review due: 12/10/2025)