How to Keep Your House Cool in Extreme Heat

In recent years, UK summers have been getting hotter and heatwaves are no longer rare events. While many welcome the sunshine, excessive indoor heat can quickly make your home uncomfortable — and in some cases, even hazardous to your health. Staying cool isn’t just about comfort; it’s about creating a safe, livable environment when temperatures soar.

From simple, low-cost solutions to investing in effective cooling systems, there are many ways to prepare for the next spell of hot weather. For those considering a long-term solution, Machine Mart air-conditioning units offer a range of options to suit different spaces and budgets. With our latest Machine Mart voucher codes, you can cut the cost of keeping cool while also making a positive difference — as we donate 20% of our profits each month to charity.

Why Extreme Heat Matters Indoors

Heatwaves are becoming more frequent and intense in the UK. In July 2022, the Met Office confirmed the UK’s highest ever recorded temperature of 40.3°C — a record-breaking event that highlighted the growing challenge of keeping homes safe and comfortable during summer. Met Office

High indoor temperatures can cause heat exhaustion or heatstroke, particularly among older adults, young children, pregnant women, and those with long-term health conditions. The NHS warns that even a few days of hot weather can be dangerous if homes are not kept cool. NHS

The UK Health Security Agency (UKHSA), in partnership with the Met Office, operates a Heat-Health Alert system that issues warnings when high temperatures are expected to impact health and public services. This allows households to prepare in advance — closing blinds, reducing indoor heat sources, and planning cooling strategies before temperatures peak. UKHSA

Effective preparation is essential: keep blinds or curtains closed on sun-facing windows during the day, ventilate your home in the cooler hours, and use fans appropriately to move air. These simple actions are consistently recommended by the Met Office and NHS to reduce overheating risks indoors. Met Office Advice · NHS Guidance

Low‑Cost and No‑Cost Ways to Keep Cool

Start with the simple wins that make the biggest difference on hot days. Close sun‑facing blinds and curtains during the day to block solar gain, then open windows when it’s cooler outside (often overnight) to flush out built‑up heat. These core steps are consistently recommended by UK authorities.

• Time your ventilation: Keep windows shut while outdoor air is hotter than indoors; ventilate in the late evening, overnight and early morning to create a cross‑breeze.
• Shade effectively: Use curtains/blinds in the day; external shading (awnings/shutters) is even more effective where available.
• Use fans smartly: Fans improve comfort when room air is below ~35 °C (Gov.UK) and are generally advised below very high temperatures (WHO guidance). Position to move cooler night air through the home rather than blowing directly at your body for long periods.
• Cut internal heat sources: Switch off unused lights and electronics; avoid oven‑heavy cooking during peak heat to reduce indoor heat load.
• Stay personally cool: Drink plenty of fluids, wear lightweight clothing, and consider cool showers or applying cool water to skin.
• Follow official alerts: Check the Heat‑Health Alerts so you can prepare your home before temperatures peak.

These measures are inexpensive yet effective, and they work even better when combined. In the next section, we’ll look at when stepping up to air‑conditioning makes sense and how to choose the right option.

The Benefits of Air‑Conditioning in UK Homes

With UK heatwaves now more frequent and intense (the Met Office confirmed a record 40.3°C in July 2022), air‑conditioning is a practical way to keep indoor temperatures safe when passive measures and fans aren’t enough. Health guidance still recommends blinds, night‑time ventilation and fans at moderate temperatures, but when homes retain heat or vulnerable people need stable conditions, an AC unit can reliably lower room temperature. Met Office · WHO

Portable vs fixed systems: Portable air‑conditioners are flexible and renter‑friendly—ideal for spot‑cooling bedrooms or home offices—while split (wall‑mounted) systems are typically quieter and more efficient for larger areas or regular use. If you want mobility and no major installation, go portable; if you need whole‑room performance with lower noise and better efficiency, consider a split system. Energy Saving Trust

Effectiveness vs fans: Fans move air and improve comfort at moderate temperatures, but they don’t remove heat. AC units actively extract heat and humidity, delivering a measurable temperature drop during severe heat. (Note: health guidance advises caution with fans at very high indoor temperatures.) WHO

Running costs and efficiency: Portable ACs use more energy than fans, so choose capacity carefully and run them strategically (for example, during peak heat or for pre‑cooling). The Energy Saving Trust notes portable units are far costlier to run than fans; pairing AC with shading and night ventilation reduces runtime and bills. Energy Saving Trust

When AC makes sense: South‑ or west‑facing rooms, top‑floor flats, bedrooms that stay warm overnight, or homes with vulnerable occupants benefit most from targeted cooling—especially when Heat‑Health Alerts are in force. UKHSA/Met Office Heat‑Health Alerts

Ready to explore options? We track savings on Machine Mart air‑conditioning units so you can cut the cost of staying cool. Check our latest Machine Mart voucher codes—and remember, every purchase through us helps support good causes, as we donate 20% of our profits each month to charity.

How to Choose the Right Air‑Conditioning Unit from Machine Mart

Selecting the right unit is about matching cooling power to your space, balancing running costs, and choosing features you’ll actually use. Here’s a clear checklist to guide your decision before you buy.

1) Size the room and pick the right BTU

• Measure the room (m²) and note ceiling height. As a rough guide, small bedrooms/home offices often suit ~7,000–9,000 BTU; medium living rooms ~9,000–12,000 BTU; larger/open‑plan areas may need 12,000 BTU+.
• Adjust for heat loads: south/west‑facing rooms, top‑floor flats, lots of glazing, or multiple occupants/devices may need the next size up.

2) Choose your format: Portable vs Split

• Portable AC: No permanent install, easy to move, great for renters or occasional use. Expect a single exhaust hose that vents out a window. Check included window kits and hose length.
• Split (fixed) systems: Quieter and typically more efficient for regular use; professional installation required. Better for larger or frequently used spaces.

3) Prioritise efficiency and running costs

• Energy rating/EER/SEER: Higher = cheaper to run. If you’ll use AC often, efficiency pays back quickly.
• Thermostat & timer: Set‑and‑forget temperature control avoids over‑cooling and trims bills.
• Eco & Sleep modes: Reduce fan/compressor speed to save energy overnight.

4) Noise and comfort features

• Noise (dB): For bedrooms, look for lower dB and a night mode.
• Dehumidify mode: Pulls moisture from the air for clammy heat; helpful in UK humidity.
• Fan speeds & swing louvres: Improve air distribution and comfort.
• Smart control: App/voice control and scheduling can cut wasted runtime.

5) Practicalities: Venting, drainage, and placement

• Window kit fit: Check your window type (slider, sash, casement) and ensure the kit will seal well to stop hot air leaking back in.
• Condensate handling: Some units evaporate moisture via the exhaust; others may need an occasional tank empty or a continuous drain hose.
• Cables & clearances: Leave space around the unit and avoid long, kinked exhaust runs.

6) Shortlist by real‑world use

• Bedroom use: Prioritise low noise, sleep mode, timer, and the right BTU for the room size.
• Home office: Look for stable thermostat control, directional airflow, and moderate BTU.
• Open‑plan areas: Consider higher‑capacity portable or a split system for sustained cooling.

When you’re ready to buy, compare models on Machine Mart by capacity (BTU), noise (dB), efficiency, and extras (dehumidify/smart control). Then reduce the upfront cost with our latest Machine Mart voucher codes—and remember, using our site helps raise money for charity as we donate 20% of our profits each month.

Energy-Efficient Cooling Strategies

Once you’ve invested in an air-conditioning unit, using it wisely can make a huge difference to running costs and environmental impact. By combining smart habits with the right features, you can stay cool without wasting energy or money.

Pair Cooling with Insulation Improvements

Even the best AC will work harder if your home leaks cool air. Simple upgrades like draught-proofing, adding reflective window films, or improving loft insulation reduce the heat coming in and the cool air escaping. This means your unit runs less often and maintains comfort for longer.

Use Timers and Programmable Thermostats

Set your AC to run only when needed. Timers and smart thermostats let you pre-cool rooms before peak heat and switch off automatically when you’re out or asleep. This helps avoid unnecessary runtime and lowers bills.

Optimise Temperature Settings

Aim for a comfortable but not excessive temperature difference between indoors and outdoors. Setting your AC to 24-26°C is usually enough to stay cool while keeping energy use in check.

Maintain Your Unit Regularly

Blocked filters, dirty coils, and obstructed vents all force your AC to work harder. Clean filters monthly in summer, check vents are clear, and follow the manufacturer’s maintenance schedule to preserve efficiency.

Combine with Passive Cooling

Close blinds and curtains on sun-facing windows during the day, ventilate in cooler hours, and use fans to circulate conditioned air. These measures reduce how long your AC needs to run, saving energy and money.

Choose Energy-Efficient Models

When upgrading, look for units with a high energy efficiency ratio (EER) or seasonal energy efficiency ratio (SEER). Inverter technology, eco-modes, and sleep functions can further cut consumption without compromising comfort.

By combining these strategies, you’ll get the best from your Machine Mart air-conditioning unit while keeping energy costs low. Don’t forget to check our latest Machine Mart voucher codes to save on your purchase — and remember, 20% of our profits go to charity each month.

How Our Voucher Codes Help You Save on Air-Conditioning

Investing in an air-conditioning unit can be a big outlay, but with our exclusive Machine Mart voucher codes, you can cut that cost instantly. We work tirelessly to source the latest and most up-to-date codes so you can enjoy real savings on top brands and models — whether you’re after a compact portable unit for a single room or a high-capacity system for larger spaces.

Finding Your Code

Visit our Machine Mart voucher codes page where you’ll find a curated list of verified discounts. Each listing clearly shows the offer, expiry date, and any minimum spend requirements, so you know exactly what you’re getting before you shop.

Applying Your Code at Checkout

• Copy the code from our site.
• Paste it into the voucher or promo code box at the Machine Mart checkout.
• Apply the code to see your total drop instantly.

Some offers may be applied automatically via tracked links — simply click through from our site and the discount will show in your basket.

Typical Savings

We’ve seen past codes offering percentages off the total order, fixed cash discounts, or even free delivery on bulky air-conditioning units. Savings vary, but every discount means more money in your pocket — and less spent on staying cool this summer.

Supporting Charity with Every Purchase

When you shop using our codes, you’re also helping to raise funds for good causes. We donate 20% of our monthly profits to charities chosen by our users, meaning your cooling upgrade also contributes to making a positive impact beyond your home.

Start your search for the perfect AC unit today and unlock extra value with our latest Machine Mart voucher codes.

Staying Cool and Supporting a Cause

Choosing the right cooling setup is smart for your home and your budget — and when you use our Machine Mart voucher codes, you also help fund great causes. Each month we donate 20% of our profits to charity, with the beneficiary selected via our community poll. That means every code you use doesn’t just lower your bill; it also contributes to real‑world impact.

How Your Savings Create Impact

• You save: Secure a verified discount on air‑conditioning units and accessories.
• Charities benefit: A share of our profits goes to the month’s chosen cause.
• Everyone wins: You get a cooler, safer home during heatwaves while supporting important work in the community.

If you’re comparing models or timing a purchase around seasonal deals, remember that buying through our links with an active code keeps that charitable cycle going. It’s a small change to your checkout — with a big difference beyond your front door.

Your Questions Answered: Staying Cool in Extreme Heat

We’ve gathered some of the most common questions UK households ask about keeping cool during hot weather. From low-cost tricks to making the most of air-conditioning, here’s what you need to know to stay comfortable and save money this summer.

1. How can I keep my house cool naturally without air conditioning?

Close sun-facing curtains and blinds during the day, ventilate in the cooler evening and early morning, and use light-coloured fabrics to reflect heat. Adding external shading, like awnings or shutters, can further block solar gain without any running costs.

2. Is a fan enough to keep my home cool in extreme heat?

Fans circulate air, which can make you feel cooler through evaporation, but they don’t lower the actual room temperature. They work best below ~35°C; at higher indoor temperatures, they may be less effective and even counter-productive for vulnerable individuals.

3. How much does air conditioning cost to install and run in UK homes?

Portable units typically range from £250–£700, with running costs of around 20–40p per hour depending on efficiency. Fixed split systems start from £1,500–£3,000 installed, but can be more energy-efficient over time. Using our Machine Mart voucher codes can help reduce upfront costs.

4. What’s the most energy-efficient way to cool a home in hot weather?

Combine passive measures (shading, insulation, ventilation) with efficient AC use. Set your unit to 24–26°C, use timers, and close off unused rooms to limit cooling to the spaces you occupy most.

5. Are portable air conditioners a good option versus fixed systems?

Portable units are flexible, renter-friendly, and require no permanent installation. However, fixed split systems are usually quieter, more efficient for regular use, and better for cooling larger spaces consistently.

6. How often should I clean my air conditioner filter during summer?

For most units, check and clean filters every 2–4 weeks during heavy use. Clean filters keep airflow efficient, improve cooling performance, and reduce strain on the system.

7. What home cooling methods can help lower energy bills?

Use timers to avoid over-cooling, close blinds during peak sun, ventilate at night, and combine fans with AC to circulate cool air. Regular maintenance of your unit also ensures it runs efficiently.

8. Can reflective paint, shutters, or greenery help prevent a home from overheating?

Yes. Reflective paints and coatings reduce heat absorption, shutters block direct sunlight, and strategically planted trees or climbing plants provide natural shading that cools the air around your home.

9. How do I ventilate my home effectively during a heatwave?

Ventilate only when outdoor air is cooler than indoors — typically late evening, overnight, and early morning. Use window fans or create a cross-breeze by opening windows on opposite sides of the home.

10. What tips can help households stay cool on a tight budget during extreme heat?

Opt for low-cost hacks like placing a bowl of ice in front of a fan, using damp sheets for evaporative cooling, unplugging heat-emitting appliances when not in use, and timing oven or hob use for cooler parts of the day.

Final Thoughts on Staying Cool in Extreme Heat

Extreme heat is no longer a rare event in the UK, and taking steps now can make your home far more comfortable when temperatures soar. From no-cost adjustments like shading windows and night-time ventilation to investing in efficient Machine Mart air-conditioning units, there’s a solution for every budget and home type.

The key is to combine smart, passive cooling habits with targeted use of technology, ensuring you stay comfortable while keeping costs under control. And when you shop with our latest Machine Mart voucher codes, you’ll not only save on your cooling setup — you’ll also be supporting our commitment to donate 20% of profits to charity each month.

Stay prepared, stay cool, and take advantage of the savings available now so you can face the next heatwave with confidence.

by Julian House 12th August 2025