Your house stores heat like a battery

If it feels like your home gets hotter every day during a heatwave, you’re not imagining it.

Homes store heat. Walls, carpets, furniture, and floors absorb warmth throughout the day and then slowly release it overnight. That’s why a house can still feel unbearably hot at midnight, even after the sun has gone down.

The biggest mistake most people make is waiting until the house already feels hot before trying to cool it. By then, the building is already heat-soaked.

The key is preventing heat from building up in the first place.

When a hot spell is forecast, start cooling strategies from the very first warm day:

Block sunlight early.
Ventilate at night.
Prevent heat from accumulating indoors.

This approach is known as night flushing.

What is night flushing?

Night flushing simply means:

Keep heat out during the day and remove it overnight.

However, don’t open windows just because it’s dark outside.

Open them when the outdoor temperature becomes lower than the indoor temperature.

A simple indoor thermometer and a weather app can help you monitor this. Houses often retain significant heat long after sunset, meaning it may still feel warm outdoors while actually being cooler than inside.

Once outdoor temperatures are lower:

Open windows.
Create cross-ventilation through the house.
Maximise airflow overnight.
Ventilate heavily before sunrise, when temperatures are usually at their lowest.

Use fans more effectively

Most people use fans incorrectly during a heatwave.

If the outside air is cooler than the air indoors:

Place a fan near a window.
Point the fan outwards, not inwards.

This helps push hot air out of the house and draws cooler air through other openings.

Upstairs windows often work best because heat naturally rises and becomes trapped on upper floors.

Stop sunlight before it enters

A huge amount of unwanted heat enters through windows.

Once sunlight passes through glass, it becomes trapped as indoor heat.

To reduce heat gain:

Close blinds before direct sunlight reaches the window.
Prioritise south-facing and west-facing rooms.
Use blackout curtains.
Install reflective window film.
Create external shade where possible.

Think of your windows as solar panels for unwanted heat.

The less sunlight that enters, the cooler your home will stay.

Reduce stored heat indoors

During a heatwave, the problem is often not just the air temperature.

Walls, carpets, furniture, mattresses, and floors continue releasing heat that was absorbed earlier in the day.

Brick homes are especially prone to this because masonry stores large amounts of heat and releases it slowly overnight.

To reduce indoor heat:

Remove thick rugs and heavy throws where possible.
Close doors to overheated rooms.
Avoid using ovens during the day.
Turn off unnecessary electronics.
Switch off lights when not needed.

Every heat source adds to the problem.

Don’t ignore humidity

Many rooms feel uncomfortable not just because they’re hot, but because they’re humid.

High humidity prevents sweat from evaporating efficiently, making it harder for your body to cool itself naturally.

To reduce humidity:

Run extractor fans during evening ventilation.
Vent cooking steam immediately.
Keep bathroom doors closed after showers.
Use a dehumidifier in particularly damp rooms.

A dehumidifier doesn’t lower air temperature significantly, but drier air often feels much cooler and more comfortable.

Create a cool refuge room

Mediterranean cultures have used this strategy for centuries.

Instead of trying to cool an entire house, focus on protecting one room from overheating.

Ideally choose:

A north-facing room.
A shaded downstairs room.
The naturally coolest area of the house.

Then:

Keep blinds closed all day.
Keep doors shut.
Direct airflow into this room.

Creating one cool refuge is often more effective than trying to cool every room.

Managing hot bedrooms

Bedrooms are often the hardest rooms to keep cool because heat rises and accumulates upstairs.

To improve sleeping conditions:

Ventilate upstairs heavily overnight.
Keep bedrooms dark during the day.
Open the loft hatch at night if safe to do so.
Close curtains before sunlight reaches bedroom windows.

Sometimes sleeping downstairs during a severe heatwave can make a significant difference.

Cool your body, not just the house

Sometimes it’s easier to cool yourself than the entire building.

Effective cooling methods include:

Cooling your wrists, neck, and feet.
Taking a cool shower before bed.
Using chilled pillowcases.
Keeping air moving across your skin.

Even warm moving air can feel much more comfortable than stagnant air because it helps sweat evaporate.

Make your bed more heat-friendly

Your bedding may be contributing to the problem.

Memory foam mattresses and toppers often retain heat and can feel particularly uncomfortable during hot weather.

Cooler sleeping setups typically prioritise airflow and breathability.

Consider:

Bamboo bedding.
Eucalyptus bedding.
Cotton percale sheets.
Lower-tog duvets.
Breathable mattress protectors.

Small changes can have a surprisingly large impact on sleep quality.

Unusual heatwave tricks that actually work

Humans were cooling themselves long before air conditioning existed.

In India and the Middle East, large fabric fans called punkahs were manually operated to move air through buildings.

Some unconventional cooling ideas can still be surprisingly effective today:

Sleep in a hammock

A hammock allows air to circulate underneath your body, helping you stay cooler overnight.

Use a tiled room

Bathrooms often feel cooler because porcelain and tiles store less heat than carpets and soft furnishings.

An empty bathtub can sometimes provide a noticeably cooler place to relax during extreme heat.

Try elevated sleeping surfaces

Some people find that sleeping on elevated mesh surfaces, such as a trampoline, feels cooler because air can circulate underneath throughout the night.

The key thing to remember

A heatwave isn’t just hot air.

It’s your entire home storing and releasing heat around you.

The people who cope best aren’t necessarily cooling the air more effectively—they’re preventing their homes from overheating in the first place.

Focus on:

Blocking sunlight.
Preventing heat build-up.
Ventilating when outdoor temperatures are lower.
Removing stored heat overnight.

Do those consistently, and your home will stay far more comfortable during even the hottest weather.

Want more ideas on keeping cool? Check out this article on 1 5 cooling gadgets that can keep you cool during a heatwave in 2026

How to keep your house cool in summer naturally