Building characteristics are the main driver of this wealth-heat disparity.
“Flats are an issue. They’re surrounded by other flats, so it’s very hard for them to lose heat,” Marshall said.
Flats and small homes are far more likely to heat up, with 30 per cent of apartments recording incidences of overheating. Houses in urban areas – where a lack of green space creates a heat sink – are also at risk.
Once the building has warmed up, it’s hard to reduce the temperature, warns Lisa Evans, a project manager for the Centre for Sustainable Energy.
Subscribe to The Big Issue
From just £3 per week
Take a print or digital subscription to The Big Issue and provide a critical lifeline to our work.
“Not many people that we work with in fuel poverty have an air-cooling system, it’s very, very few,” she said.
“An awful lot of people haven’t got fans. One of our clients was telling a caseworker today that she wasn’t going to put her fan on because she was worried about the price.”
It costs roughly 3 pence to run a 50 watt fan for an hour.
“It’s not huge. But for people on very, very low incomes that are really struggling, every penny counts,” Evans said.
“And it adds up over a longer period of time.”
The extreme heat can have deadly consequences. Every year, around 2000 people die in the UK from heat-related conditions – a number that could triple by 2050 as global temperatures increase.
The rising temperatures have led to calls for a massive overhaul of Britain’s houses, which need to be adapted and insulated for extreme weather.
Stop Mass Homelessness
Help us stop mass homelessness
Unless we act, the UK is facing a homelessness crisis
Last year, the government introduced a “Future Homes Standard”, a policy which requires new-builds to be well-ventilated and temperature-resistant. But this standard does not apply to millions of existing homes that heat up in the summer months.
“We need to adapt houses. Ideally, we want non mechanical methods, basically not a fan or an air conditioner,” Marshall said.
“Using shutters and shading on windows, for example. Once they’re there they don’t incur a cost and they don’t use energy.”
And the families that overheat in summer are also the most likely to freeze in winter, Evans cautions. Done wrong, insulation can trap heat in during the summer. Done right, it can help keep the house cool.
“Insulation is a really, really big help, not only in the winter to keep the heat in, but to keep the heat out in the summer,” she said.
“We’d really like to see a big insulation, national insulation scheme rollout. You know, just to make sure that houses are as energy efficient as possible.
“It’s not a sticking plaster… it’s a permanent solution.”
In the meantime, there are things that you can do to stay cool as the mercury climbs.
Evans recommends wetting a towel and putting it around your neck, putting your feet in some water, and drawing the curtains to keep the bright sunlight out. Keep the windows on the south facing side shut during the daytime, and put the fan by an open window at cooler hours of the day.
“If you have a fan on in a room without the windows open, and it’s really stifling in there, the fan just throws hot air around,” Evans said.
“It just acts like an oven.”