A viral £1.50 hack using kitchen foil to cool down a house does work, but it comes with a significant safety warning that could lead to costly window repairs. Senior Social News reporter Zahna Eklund tested the trick in her bedroom, which regularly hits 30°C during UK heatwaves.
The hack involves taping large strips of aluminium foil over windows to reflect sunlight. Eklund covered half her window and immediately felt a temperature drop. Her phone thermometer showed the room fell from 28°C to 26°C after a dinner break, and by the next morning it was 23°C. Sleeping became easier, though she still used a fan briefly.
How the Hack Works
The theory is that glass magnifies heat, while shiny foil reflects it, bouncing sunlight away and preventing heat from entering. Eklund confirmed the effect was noticeable, but not dramatic enough to eliminate the need for a fan entirely.
Safety Warning: Place Foil Outside, Not Inside
Adam Pawson, Head of Digital at Safestyle, warned that foil should be placed on the outside of windows. He told Ideal Home: “Blocking your windows with tin foil will help to keep your rooms cooler… However, one mistake people make is placing the foil on the inside of the window. It is really important to be careful to place the tin foil on the outside of your windows rather than the inside to prevent the glass from getting too hot.”
Sun reflecting off interior foil can overheat the glass, potentially breaking the window seal and requiring replacement. Experts at H2ouse confirmed the foil itself is safe: “The heat of the sun cannot melt the aluminium foil… exposure to heat will not radiate harmful toxins into your house.”
Practical Drawbacks
Placing foil on outside upstairs windows may require ladders and could draw odd looks from neighbours. Eklund noted that the hassle and potential damage risk might make a desk fan a better option for many.
