Keeping a house cool during a heatwave can be achieved with a 79p roll of kitchen foil from Home Bargains, as the reflective material helps block solar radiation from entering through windows. The Buffalo Kitchen Foil, measuring 10 metres in length, is being promoted as a low-cost alternative to electric fans and cooling gadgets.
How the foil trick works
Placing foil over sun-facing windows reflects a large proportion of solar radiation before it passes through the glass, reducing indoor temperatures. According to the UK Centre for Sustainable Energy, preventing sunlight from entering through windows is one of the most effective ways to lower indoor heat. The organisation recommends using external shading where possible, but notes that reflective materials can also help reduce solar heat gain.
The Energy Saving Trust advises closing curtains, blinds or other window coverings on sun-facing windows during the day to stop heat building up indoors. Blocking solar radiation before it heats internal rooms is far more effective than trying to cool them afterwards, the trust says.
Application and effectiveness
The foil can be applied to the inside or outside of windows. While foil on the outside is generally more effective, many households place it on the inside as a temporary measure during extreme heat. The trick is particularly useful as parts of the UK have experienced temperatures approaching 38°C, prompting the Met Office to issue rare red heat warnings. Forecasters warn that homes can retain heat long after sunset, making nights uncomfortable.
Official health advice
The NHS recommends keeping windows and curtains closed in rooms exposed to direct sunlight during the hottest part of the day, then opening windows again once outside air cools. These simple steps can help reduce the risk of overheating during prolonged hot spells.
