How to keep your bedroom cool at night in a heatwave

Keep the sun out during the day

A bedroom that bakes all afternoon stays hot long after bedtime. The UK Health Security Agency's Beat the Heat advice is to close blinds and curtains on windows in direct sunlight during the day, and to close external shutters or shades if you have them. Its keep cool at home checklist calls roller blinds and awnings very effective, and notes that plants outside can shade windows, especially south-facing ones.

Outside shading works best because it stops the sun before it reaches the glass. Inside, close the curtains before the sun reaches that window, not once the room is already hot. The NHS gives the same advice: keep windows, curtains and blinds closed during the day and open them at night once it's cooler outside.

• Turn off lights and anything electrical you're not using, as UKHSA suggests
• Check the heating is off, including towel rails and underfloor heating
• Cook at cooler times of day

How to keep a bedroom cool at night: a heatwave routine

1. 1

   Morning

   Close the curtains or blinds on any bedroom window the sun will reach. If it's already warmer outside than in, close the windows too.

2. 2

   Afternoon

   Keep the bedroom door shut and the room dark. Opening windows while the air outside is hotter only lets more heat in.

3. 3

   Evening

   Once the air outside feels cooler than inside, open the windows wide where it's safe. Windows on opposite sides of the home, with the doors between them open, get air moving through. The Sleep Charity suggests opening doors as well as windows to make a cool draught.

4. 4

   Before bed

   Have a cool shower or bath, which The Sleep Charity says lowers your core body temperature. Keep a glass of cold water by the bed, and go easy on caffeine, alcohol and big meals late in the evening.

5. 5

   Overnight

   Sleep under a cotton sheet in light cotton nightwear. If the bedroom is still too hot, UKHSA's advice is to move to a cooler part of the home to sleep.

Opening windows safely

Night-time airing is the cheapest cooling there is. Keep it safe, especially with children in the house.

• Fit restrictors or locks to upstairs windows, as RoSPA advises, so they open enough for air but not for a child. Choose quick-release ones, so you can still get out in a fire
• Never put a bed, chest of drawers or any furniture a toddler could climb near a window. RoSPA singles out bedrooms
• On a sash window, open the top half: Lambeth Council notes that growing children can push the bottom open
• Don't leave ground-floor windows wide open while you're asleep or out
• Only open up when the air outside is cooler than inside, as UKHSA advises

Fans: where and how

A fan doesn't cool the air. It moves it, which helps sweat evaporate and makes you feel cooler. UKHSA's advice is to use electric fans if the air temperature is below 35°C, and not to aim a fan directly at your body, because that can lead to dehydration.

Point the fan so it moves air around the room or across the bed, rather than straight at you all night. In the evening, a fan near an open window can help draw cooler outside air in. For a baby, the Lullaby Trust says a fan can cool the room, but don't aim it at the baby.

What works and what doesn't

Top-floor and loft bedrooms

These are usually the hottest rooms in the home, and the official guidance agrees. UKHSA's checklist lists top-floor flats as more likely to overheat because heat rises, along with homes with windows on only one side, large east, west or south-facing windows without shade, and highly insulated homes, which can trap heat.

Shade the windows from outside if you can, and air the room hard overnight. If it still won't come down, sleep on a lower floor during a heatwave. If a loft bedroom is still too hot every summer despite all this, that's when fixed cooling is worth considering.

How to keep a bedroom cool in summer for a baby

The Lullaby Trust recommends a room temperature of 16 to 20°C for babies, as a guide, and suggests a room thermometer where your baby sleeps, because it's hard to judge by feel. To check whether your baby is too hot, feel their chest or the back of their neck, not their hands or feet. If the skin is hot or sweaty, take off a layer of bedding or clothing.

In hot weather, the Lullaby Trust suggests lighter bedding and clothing, opening the bedroom door and a window if it's safe, and keeping the cot out of direct sunlight. Babies don't need hats indoors and shouldn't sleep under a duvet or quilt. Fully breastfed babies may feed more often in the heat, and formula-fed babies can be offered a little cooled boiled water.

UKHSA lists children aged 5 and under among those at higher risk in hot weather. Its advice is to make sure there's enough air flow, remove excess clothing and check on them regularly.

Older people and anyone at higher risk

UKHSA's list of people at higher risk in hot weather includes adults aged 65 and over, people with long-term health conditions, particularly heart and breathing problems, pregnant women, people taking certain medicines and people who live alone. If someone you know is on that list, check in during a heatwave, help them shade and air their home, and make sure their bedroom isn't the hottest room in the house.

When air conditioning makes sense

If the bedroom is still too hot to sleep after shading, airing and a fan, or someone at higher risk sleeps there, a fixed system is the reliable answer. It also lets you keep the windows shut on noisy or unsafe nights.

Bedroom units are quieter than most people expect. Premium 2.5 kW wall units from Daikin, Mitsubishi Electric, Panasonic and LG list 19 dB(A) on their quietest setting. Sleep settings ease the temperature up gently through the night, and dry mode takes moisture out of muggy air. The systems we fit heat as well as cool, so the same unit warms the room in winter. That also matters for planning: in England, a unit used only for cooling can't use the permitted development rules.

For a nursery, we place the unit so the air never points at the cot, and a room thermometer helps you keep to the Lullaby Trust's range.

What a bedroom unit costs

A single bedroom unit, fully fitted. Your fixed price comes after a free survey.

• A bedroom or study

  2.5 kW wall unit, 5 m pipe, fitted in a day

  from£1,850inc. VAT

Bedroom heat questions