Warning not to use electric fans during heatwave as weather maps hit 33C

Experts are urging people not to use fans during heatwave conditions as a sweltering 33C wall of heat sweeps over the UK.

Weather maps show the temperatures will only climb on Monday, after what is sure to be a baking enough Sunday.

The Met Office says Monday's temperatures will peak at 33C in some parts of England, while the mercury remains high on Tuesday and Wednesday at 28C and 26C respectively.

It might sound counterintuitive but fans aren't the answer when the heat gets really stifling, for a very surprising reason.

British homes are awful places to be in a heatwave. That's because, due to our moderate climate and cold winters, they're made to trap heat in, using heavy duty bricks, insulation, double or even triple glazing and thick roof tiles to keep as much of the heat inside as possible.

That's all great on a freezing December morning but in the grip of a sweaty and humid heatwave, it can become a real struggle to battle through the hot conditions especially as the vast majority of UK homes don't have air conditioning units.

But a fan isn't always the answer. Using a fan during a heatwave can actually make your room even hotter. According to the Government's own heatwave plan, electric fans only work in temperatures under 35C, so in a proper heatwave, they do nothing to reduce you feeling poorly.

But at any temperature, fans don't actually cool down the room, they simply move the air around. So although you might feel a bit better with one in your face, the room is just as hot as it was before and it could actually lull you into a false sense of security if you use a fan instead of staying hydrated or cooling the room properly.

The best thing to do is to open as many windows as possible, try to shade windows, and keep cool with regular water or even cold showers, and stay out of direct sunlight.

Energy firm OVO warns about using fans: "Electric fans can really help to cool your home and give you instant relief. But they can use a lot of energy, and don’t actually cool the air. Since heat rises, the coolest air in your house is going to be at floor level. So it makes sense to set your fan on the floor and point it upwards. Position it so it points outwards towards the opposite wall, with no large objects in the way. This trick bounces the cooler air back into the room, to cool the overall temperature. If you’ve got a timer on your fan, this is a good way to make sure it’s only switched on as much as it’s needed."

The government's own advice adds: "Use electric fans if the air temperature is below 35°C, but do not aim the fan directly at your body as this can lead to dehydration.

"Hot weather can increase the risk of heart attack, stroke, lung problems and other diseases. Older people, babies and young children are more likely to be unwell from hot weather because their bodies are less able to regulate temperature. People with underlying medical conditions can also be vulnerable to the effects of hot weather."

"Many of the harms linked to heat exposure are preventable if a few simple actions are taken. During the summer, UKHSA will work with the Met Office to issue alerts alongside the weather forecast if the weather is so hot that it has the potential to affect people's health, and will help you to take steps to protect yourself and others."

Met Office Deputy Chief Meteorologist, Dan Holley, said: “We expect to see a relatively brief hotter and more humid spell of weather for Sunday and Monday, before these hotter conditions recede on Tuesday, allowing more unsettled conditions to return.

“This change to hotter conditions is caused, in part, by the effects of Tropical Storm Debby in North America. Debby is helping to strengthen the jet stream, causing it to meander over the Atlantic. This will allow hot air over France to move into the UK later this weekend, and early next week.”