Introduction

There are few things more frustrating than lying awake on a hot, sticky night. You feel exhausted, yet every time you begin to drift off, you wake up feeling too warm, uncomfortable and restless.

If you've struggled to sleep during a heatwave, you're certainly not alone. Warm nights make it harder for your body to reach the temperature needed for quality sleep, meaning you may take longer to fall asleep, wake more frequently and feel less refreshed the following morning.

The good news is that you don't necessarily need expensive air conditioning to improve your sleep. A combination of simple changes to your bedroom, bedding and evening routine can make a noticeable difference.

In this guide, we'll explain why heat affects your sleep and share practical, evidence-informed tips to help you stay cooler and sleep better during hot weather.

Why Is It Harder to Sleep During a Heatwave?

Your body follows a natural 24-hour cycle known as the circadian rhythm. As bedtime approaches, your core body temperature gradually falls. This drop in temperature is one of the signals that tells your brain it's time to sleep.

During a heatwave, your body has to work much harder to lose heat. If your bedroom remains hot throughout the evening, this cooling process becomes less effective. As a result, you may:

Take longer to fall asleep.

Wake up repeatedly throughout the night.

Spend less time in deep, restorative sleep.

Feel tired and irritable the following day.

Humidity can make matters even worse because sweat evaporates less efficiently, reducing your body's ability to cool itself naturally.

1. Keep Your Bedroom Cool Throughout the Day

One of the biggest mistakes people make is trying to cool the bedroom only when they go to bed.

By that point, walls, furniture and flooring have already absorbed heat throughout the day and continue releasing it well into the evening.

Instead:

Close curtains or blackout blinds before the sun reaches the windows.

Keep windows shut while the outdoor temperature is higher than indoors.

Turn off unnecessary electrical equipment that generates heat.

Avoid using ovens or tumble dryers if possible.

South-facing bedrooms may remain significantly warmer than north-facing rooms, so preventing heat build-up is often more effective than trying to remove it later.

2. Create Better Airflow

Fresh moving air helps your body cool itself more efficiently.

If the outside air becomes cooler during the evening:

Open windows on opposite sides of the house.

Create cross-ventilation wherever possible.

Leave internal doors open to improve airflow.

Open loft windows if appropriate to allow hot air to escape.

Many people open every window all day, but if it's hotter outside than inside, this often makes the house even warmer.

3. Make Your Fan Work Harder

Fans don't actually cool the air—they move it around your body, helping sweat evaporate more effectively.

To get the most from a fan:

Position it near your bed rather than across the room.

Use oscillation rather than one fixed position.

Set a timer so it switches off after you've fallen asleep.

Place frozen water bottles or a bowl of ice in front of the airflow for a temporary cooling effect.

Some people also find the gentle white noise from a fan helps them drift off more easily.

4. Switch to Lightweight Bedding

Your duvet may be trapping far more heat than you realise.

During particularly warm nights consider:

Sleeping under a cotton sheet instead of a duvet.

Choosing breathable cotton or linen bedding.

Avoiding thick synthetic materials that trap heat.

Washing bedding regularly to keep fabrics fresh and breathable.

Natural fibres generally allow heat and moisture to escape more effectively than polyester.

5. Wear Breathable Sleepwear

What you wear to bed can have a surprising impact on sleep quality.

Loose-fitting cotton pyjamas often help wick moisture away from the skin more effectively than tight-fitting synthetic clothing.

Some people prefer sleeping with minimal clothing during a heatwave, while others find lightweight cotton clothing more comfortable because it absorbs perspiration.

The best choice is whichever helps you remain cool without feeling clammy.

6. Take a Lukewarm Shower Before Bed

Although jumping into an icy shower sounds appealing, extremely cold water can cause blood vessels near the skin to constrict.

This may actually reduce heat loss once you step out.

Instead:

Take a cool or lukewarm shower.

Allow your body to cool gradually.

Dry yourself before getting into bed.

Many people find this lowers their body temperature enough to fall asleep more comfortably.

7. Cool Key Areas of Your Body

Certain parts of the body lose heat more effectively than others.

Try placing a cool, damp flannel on your:

Neck

Wrists

Forehead

Ankles

Alternatively, wrap a cold pack or chilled hot water bottle in a towel before placing it against the body.

Never apply ice directly to your skin, as this can cause discomfort or even cold injury.

8. Stay Hydrated

Even mild dehydration can make it more difficult for your body to regulate temperature.

Aim to:

Drink water regularly throughout the day.

Keep a bottle of water beside your bed.

Replace fluids lost through sweating.

However, avoid drinking excessive amounts immediately before bedtime, as repeated trips to the toilet may disturb your sleep.

It's also worth limiting alcohol during heatwaves. Although it may make you feel sleepy initially, alcohol disrupts sleep quality and contributes to dehydration.

Similarly, large amounts of caffeine late in the day can make falling asleep more difficult.

9. Adjust Your Evening Routine

Your evening habits influence both your body temperature and your ability to fall asleep.

During very hot weather:

Exercise earlier in the day if possible.

Eat lighter evening meals.

Avoid spicy foods close to bedtime if they make you sweat.

Reduce screen brightness during the final hour before bed.

Keep your bedroom dark and quiet.

Giving your body time to cool naturally before sleep can improve overall sleep quality.

10. Sleep in the Coolest Room

Remember that heat rises.

If your upstairs bedroom feels unbearable, consider temporarily sleeping:

In a downstairs room.

In a guest room.

On a sofa if it's significantly cooler.

Some people even place a mattress on the floor, where temperatures may be slightly lower than higher up in the room.

While it may not be your usual sleeping arrangement, one or two cooler nights can leave you feeling much more rested.

11. Avoid Common Heatwave Sleep Mistakes

When people become desperate for sleep, they often try methods that sound helpful but have little benefit.

Common mistakes include:

Leaving windows open all day

This often lets even hotter air into the house.

Taking an ice-cold shower

This may feel refreshing briefly but can reduce heat loss afterwards.

Drinking alcohol to help sleep

Although you may fall asleep faster, your sleep quality usually suffers.

Sleeping directly under a fan all night

Some people wake with dry eyes, dry throat or stiff muscles.

Using heavy duvets "just in case"

You'll almost certainly overheat during the night.

12. What If You Still Can't Sleep?

A poor night's sleep can be frustrating, but try not to panic.

Instead:

Get up at your normal time.

Avoid spending all morning in bed.

Take a short nap of around 20–30 minutes if absolutely necessary.

Keep your normal bedtime the following evening.

One bad night rarely causes lasting problems, and maintaining your usual routine helps your body return to its normal sleep pattern more quickly.

When Hot Weather Becomes Dangerous

Difficulty sleeping is common during a heatwave, but excessive heat can sometimes become a medical emergency.

Seek urgent medical advice if someone develops symptoms such as:

Confusion.

Severe dizziness.

Fainting.

Persistent vomiting.

Difficulty breathing.

Very high body temperature.

Hot, dry skin or signs they are unable to cool down.

Babies, older adults, pregnant women and people with long-term medical conditions may be particularly vulnerable during prolonged periods of extreme heat.

Frequently Asked Questions

Should I leave my windows open during a heatwave?

Only if the outside temperature is cooler than indoors. During the hottest part of the day, keeping windows closed and curtains shut usually helps keep the house cooler.

Is it safe to sleep with a fan on all night?

For most healthy adults, yes. However, some people experience dry eyes, dry mouth or muscle stiffness. Using a timer or oscillating setting may improve comfort.

Does putting bedding in the freezer work?

Cooling a pillowcase or sheet for a short time may feel pleasant, but avoid making bedding damp, as moisture can quickly become uncomfortable in warm weather.

Is a cold shower better than a warm one?

A cool or lukewarm shower is generally preferable. Extremely cold water may briefly reduce your body's ability to lose heat afterwards.

What bedding is best during summer?

Natural fabrics such as cotton and linen tend to be more breathable than synthetic materials and can help improve comfort on hot nights.

Final Thoughts

Sleeping during a heatwave isn't always easy, but small changes can make a big difference. Keeping your home cool during the day, improving airflow at night, choosing breathable bedding, staying well hydrated and adjusting your evening routine all help your body lose heat more effectively.

Rather than relying on a single trick, combine several of these strategies to create a cooler, more comfortable sleeping environment. While you may not be able to control the weather outside, you can give yourself the best possible chance of getting the restful night's sleep your body needs.