If you've lived through a British heatwave, you know the drill. The Met Office issues an amber warning, the news starts running segments on egg-frying pavements, and your house — beautifully designed to trap every last scrap of winter warmth — turns into an oven you can't switch off.
In July 2022, the UK hit 40.3°C at Coningsby in Lincolnshire, smashing the previous record by over a degree. It wasn't a freak one-off either. Climate scientists are clear: heatwaves like that are going to keep happening, and they're going to get worse. The summers of 2023 and 2025 reinforced the point.
The problem is that British homes are fundamentally built to keep heat in. Cavity wall insulation, double glazing, draught-proofing — all brilliant in January, all working against you in August. And let's be honest, most of us don't have air conditioning, and at £3,000–£5,000 for a proper multi-split system, that's not changing any time soon.
So what can you actually do? Here are ten things that genuinely help — some are free, some cost a little, and all of them are more practical than moving to Scotland.
1 Close Curtains and Blinds Before the Heat Arrives
This sounds almost insultingly simple, but it's one of the most effective things you can do. Solar heat gain through windows accounts for a huge proportion of indoor overheating — some estimates put it at 25–30% of unwanted heat in a typical home.
The key is to close curtains and blinds before your rooms heat up, not after. If you're heading out for the day, close everything on the south and west-facing sides of the house before you leave in the morning. By the time you get home, the difference compared to leaving them open is genuinely striking.
Lighter-coloured curtains with a reflective or thermal lining work best. Heavy dark curtains absorb the heat and radiate it inward — they'll help a bit, but nowhere near as much as a light-coloured, lined option.
2 Use Cross-Ventilation at Night
Once the temperature outside drops below the temperature inside — usually from around 9pm onwards — open windows on opposite sides of your home. This creates a cross-draught that flushes warm air out and pulls cooler air through.
If you can, open windows at different heights too. Hot air rises, so a high window on one side and a lower one on the other creates a natural chimney effect. Even a small window cracked open on the leeward side makes a noticeable difference.
A word on security: if you're leaving windows open overnight, consider window restrictors or lockable ventilation stays. They let you keep windows open enough for airflow without making your home vulnerable.
3 Hang Wet Towels or Sheets
Old-fashioned but surprisingly effective. Hanging a damp (not dripping) sheet or large towel in front of an open window or in a doorway creates a basic evaporative cooling effect. As the water evaporates, it draws heat from the surrounding air.
You can also drape a damp towel over the back of a chair and position a fan behind it. It's essentially a DIY evaporative cooler — it won't rival air conditioning, but it can knock a couple of degrees off the temperature in a small room. In the worst of a heatwave, a couple of degrees matters.
4 Position Fans Strategically
A fan doesn't actually cool the air — it moves it. But how you position a fan makes a massive difference to how much relief you feel.
- Facing outward in the hottest room: Place a fan in the window of your hottest room, blowing outward. It pushes hot air out and draws cooler air in through other openings.
- Bowl of ice trick: Put a shallow bowl of ice or frozen water bottles in front of a fan. The air passing over the ice picks up the chill. It's temporary, but it works well for sleeping.
- Ceiling fans anticlockwise: If you have ceiling fans, set them to run anticlockwise (looking up). This pushes air straight down, creating a wind-chill effect on your skin.
The worst thing you can do with a fan is leave it running in an empty, closed room — it's just churning warm air and adding a tiny bit of motor heat. Fans cool people, not rooms.
5 Avoid Cooking Indoors
An oven running at 200°C pumps a remarkable amount of heat into your kitchen — and from there, into the rest of the house. During a hot spell, lean into cold meals: salads, sandwiches, gazpacho, things from the fridge.
If you do want something hot, a BBQ outside is the obvious choice. Failing that, a microwave generates far less ambient heat than an oven or a hob. Same goes for slow cookers and air fryers — they're better contained and produce less waste heat.
And while we're on kitchen heat sources: your dishwasher, tumble dryer, and washing machine all generate meaningful warmth. Run them in the evening if you can, or better yet, dry clothes outside.
6 Apply Reflective Window Film
How window film keeps your home cool
Here's the thing about windows: they're designed to let light in, and light carries heat. Specifically, it's the near-infrared part of the solar spectrum — invisible to the eye, but responsible for the majority of the heat gain you feel when sunlight pours through glass.
Reflective window film works by adding a microscopically thin layer to your existing glass that selectively rejects infrared energy at the glass surface, before it enters your room. Modern ceramic films can block up to 80–90% of solar heat while still letting plenty of visible light through — so your rooms stay bright, but dramatically cooler.
Think of it this way: instead of letting the heat in and then trying to get rid of it with fans and curtains, you're stopping it at the source. That's a fundamentally different approach, and it's why window film often outperforms interior blinds. Blinds absorb heat and re-radiate it into the room. Film reflects it back out through the glass before it's inside your home in the first place.
It's particularly effective on south and west-facing windows, conservatories and glass extensions, and any room where you've noticed the sun turns it into a greenhouse from late morning onwards. A professional installation takes a few hours, there's no building work, and the film is completely reversible if you ever change your mind.
Unlike air conditioning, there are no running costs and no maintenance. The film sits quietly on your glass, working every sunny day, summer and winter (it also helps with heat retention in colder months). Most quality films come with a 10–15 year manufacturer warranty.
7 Close Internal Doors
Heat migrates. If your kitchen is 30°C and your north-facing bedroom is 24°C, leaving the doors open means the whole house converges somewhere in between. Closing internal doors compartmentalises your home and lets you keep the coolest rooms cool.
This is especially useful if you have rooms you're not using during the day. Close the doors, close the curtains, and let those rooms stay as cool as possible. When bedtime rolls around, you'll have a meaningfully cooler room to sleep in.
It works in reverse too: if one room gets hammered by afternoon sun (looking at you, west-facing living rooms), closing the door stops that heat bleeding into the hallway and the rest of the house.
8 Use a Dehumidifier
It's not always pure heat that makes a UK heatwave so uncomfortable — it's humidity. British summers tend to be muggy rather than dry, and when relative humidity climbs above 60%, your body's ability to cool itself through sweating drops off sharply. You feel hotter than the thermometer says you should.
A decent dehumidifier pulls moisture out of the air, which makes the same temperature feel noticeably more bearable. A room at 28°C with 40% humidity feels dramatically different from the same room at 28°C with 70% humidity. It won't change the number on your thermometer, but it'll change how you feel — and honestly, that's what matters.
Modern dehumidifiers are relatively energy-efficient and quiet. If you're running one, keep doors and windows in that room closed so it can actually do its job.
9 Shade Your Glazing from the Outside
External shading is significantly more effective than internal shading — roughly two to three times more, by most estimates. The reason is physics: if you block the sunlight before it hits the glass, the heat never enters the building. Internal blinds can only work with heat that's already inside.
Options range from the simple to the structural:
- External roller blinds or shutters — common across southern Europe for good reason. Increasingly available in the UK.
- Awnings — particularly good for patio doors and large south-facing windows.
- Shade sails or temporary canopies — a budget-friendly option that works surprisingly well.
- Planting — deciduous trees and climbing plants provide shade in summer and let light through in winter. A long-term investment, but a beautiful one.
Even a temporary measure like propping a large piece of cardboard or reflective material against the outside of a window can help in a pinch. It's not pretty, but during a level 3 heat health alert, aesthetics tend to take a back seat.
10 Insulate Your Loft
This sounds counterintuitive — isn't insulation for keeping heat in? Yes, but it works both ways. In summer, your roof absorbs an enormous amount of solar radiation. If your loft isn't insulated, that heat radiates straight down through the ceiling into your top-floor rooms.
Proper loft insulation (the government recommends at least 270mm of mineral wool) acts as a barrier. It keeps heat out in summer just as it keeps heat in during winter. If your upstairs is always significantly hotter than your ground floor during a heatwave, inadequate loft insulation is likely a big part of the reason.
There are also grants available. The Great British Insulation Scheme and ECO4 may cover part or all of the cost depending on your circumstances — worth checking even if you think you might not qualify.
Putting It All Together
No single tip here is a silver bullet. The most comfortable homes during a UK heatwave are the ones that combine several of these approaches. Close the curtains during the day, cross-ventilate at night, use fans intelligently, and address the windows that let the most heat in.
If your home suffers every summer — and particularly if you have south-facing glazing, a conservatory, or rooms that become genuinely unliveable — it's worth thinking about the permanent fixes alongside the quick wins. Window film vs air conditioning is a comparison more people are making each year, especially as UK summers get hotter and the cost of AC keeps climbing.
The reality is that UK homes weren't designed for the climate we're now living in. But with a few smart changes — some free, some affordable, and none requiring planning permission — you can make a significant difference to how your home handles the heat.
Quick summary: Close curtains early, cross-ventilate at night, position fans to push hot air out, avoid the oven, hang damp towels, apply reflective window film, close internal doors, dehumidify the air, shade glazing externally, and insulate your loft. Do even half of these and you'll notice a real difference.
Thinking about window film?
We install solar control film across London and the South East — no building work, no mess, and a noticeable drop in temperature from day one. Get a free, no-obligation quote.
Get a Free Quote