Should You Keep Your Windows Open or Closed During a Heatwave?

When a heatwave hits, many homes get very hot and stuffy, especially at night. Most people think opening the windows is the best way to cool things down. But experts say it is not always that simple — and knowing when to open or close your windows can make a big difference in how comfortable your home feels.

Professor Amin Al-Habaibeh is a scientist who studies how heat moves through buildings at Nottingham Trent University. He says there are two main ways heat gets into a house: sunlight coming through windows and hot air drifting in from outside. He also warns about something called the greenhouse effect, where heat gets trapped inside a room and makes it even warmer than it is outdoors.

Professor Al-Habaibeh says the key rule is simple. Open windows when the temperature inside the house is higher than the temperature outside, and keep them closed if it is hotter outside. That way, you are not letting hot air in and making things worse.

He also has advice for people who have a conservatory, which is a glass-walled room attached to a house. He says it is important to keep the conservatory's windows open during the day to let heat escape. It is also a good idea to close the door between the conservatory and the rest of the house, so that trapped heat does not spread to other rooms.

Dr. Lindsay Browning is a sleep expert who agrees that closed windows are usually better during the hottest part of the day. She says that once the sun goes down and the outside air starts to cool, that is the right time to open windows and let in a fresh breeze. Opening windows at night helps air move through the room and makes it easier to sleep.

Both experts agree that keeping curtains and blinds closed during the day is very important. Sunlight shining through glass can heat up a room quickly, just like a greenhouse. Blocking the sun with curtains or blinds stops this from happening and helps the room stay cool.

The NHS also has tips for staying safe in hot weather. They recommend drinking plenty of water, staying out of the sun between 11am and 3pm, and avoiding hard exercise during the hottest part of the day. These steps help protect your body from the dangers of too much heat.

NHS Property Services adds that you should open windows on the shaded side of your home, not the sunny side. If your home has air conditioning, they say to keep all windows closed so the cool air stays inside. Following these tips can help you and your family stay cool and safe when temperatures rise.