Summer has finally arrived as UK weather maps turn bright red and a blistering heatwave is set to bake the country this week.

Forecasters have issued a yellow ‘heat health alert’ due to the sweltering weather on the way acros the UK.

It means we're all set for very high temperatures with forecasts ranging anywhere from 26C to 30C in some parts of the UK.

Now everyone is looking for any way to keep cool and reduce the temperature in their house, preferably as cheaply as possible.

While fans and aircon do work, they are increasingly expensive to run thanks to the cost of living crisis and do bring with them potential health problems.

And of course homes in the UK are largely built to trap and keep heat in, thanks to our usually moderate climate, which certainly doesn't help.

But there is a little known trick to keeping your house cool which needs only a £1.20 roll of tin foil or kitchen foil - such as that sold in Asda as well as other supermarkets like Tesco, Morrisons, Sainsbury's and Aldi, although the price has jumped from 68p to £1.20 in the past two years.

People desperately trying to keep cool have urged others to roll out kitchen tin foil and spread it in your windows, especially any windows that’s in direct sunlight.

Normally, when direct sunlight shines through a window, it magnifies the heat of the sun and makes your house even warmer - this is how greenhouses work to keep plants warm inside.

But foil works by reflecting the sun off the window, sending it back outside instead.

Other options include keeping your window open but your curtains drawn, blocking direct sunlight from entering. But this will still warm your room slightly through the curtains, whereas foil reflects the sun more.

You may remember that foil reflecting heat works in winter too, after people were advised to hang strips of tin foil behind radiators to help them reflect their heat into the room.

Is hanging tin foil in windows in a heatwave safe?

The other advantages of tin foil or 'aluminium foil' are that it's non-toxic and it doesn't melt until it hits 660C, so even in this heatwave, it's going to manage perfectly fine with hundreds of degrees to spare and you don't have to worry about the foil melting in the sun.

Ways to keep your house cool in a heatwave

Other tips to keep a house cool in a heatwave include:

Opening windows and doors, and keeping doors open to allow air to circulate through the house.

You can also place bowls of water through the house in different rooms that will evaporate into the air to help keep the air temperature cool. House plants also keep a home cooler. They act as natural air conditioners, regulating the temperature of a room by generating moisture into the air in a process called transpiration.

You can also turn off appliances that aren't being used. Every appliance, such as an oven, toaster, laptop or a PlayStation, could generate small amounts of heat on standby that all contribute to the general heat level of a house.

The same goes when charging items like your phone, the small amount of heat generated could help warm a room slightly so it's best to charge at night.

Energy saving LED lightbulbs also will help cool your house. Regular lightbulbs such as Halogen produce an enormous amount of heat as they light a room and several Halogen lights or spotlights can warm a room up quickly at night.

Try swapping to energy saving LEDs and keep lights off as much as possible - which will also save you money.