A late 19th-century experiment once claimed that a frog placed in a pan of water wouldn’t jump out if the water was gradually heated—ultimately meeting a grim fate. While its scientific accuracy is debated, the story has endured as a powerful metaphor.

Some scientists, including Dr Eugene Mohareb from the University of Reading, believe it also reflects our own reluctance to respond to steadily rising temperatures.

“Extreme heat events have been creeping up on us over the past 25 years,” he said. “Like with the frog and boiling water, we haven’t noticed how much more frequent they’ve become.”

Statistics show that June heatwaves are becoming increasingly frequent and intense. So, how can we better protect our homes—not only from the cold of winter but also the growing heat of summer?

As counterintuitive as it might seem, the same insulation designed to keep us warm in winter can help keep our homes cool in the summer. Experts in housebuilding point out that proper insulation—particularly in walls—acts as a barrier against external heat.

Staff at the National Self Build and Renovation Centre in Swindon report a significant rise in enquiries from self-builders keen to understand how insulation can work year-round.

Managing director Harvey Fremlin said: “The key is in the detail with insulation.

“The fabric of your building will be breathable so it will retain the heat in the colder months, with the installation products designed to do that, but they’re also designed to block out solar gain – the heating from the sun.”

The government has announced its intention to build 1.5 million new homes over the next four years. As part of this strategy, it is encouraging developers to install air source heat pumps to reduce carbon emissions while providing heating.

Crucially, when properly specified and installed, these systems can also offer cooling in warmer months. Mr Fremlin explains that modern mechanical ventilation and heat recovery systems filter outdoor air and bring fresh air into homes—warming it in winter and cooling it in summer.

Upgrading from double to triple glazing is another way to mitigate overheating, as the additional pane helps reflect solar radiation away from the home.

While many of these solutions involve a significant upfront cost, some options are becoming more affordable. One such example is electric shutters. Commonplace in southern Europe, these shutters can block out the sun and help regulate indoor temperatures. Mr Fremlin believes that as extreme heat events become more common in the UK, more people will be inclined to install them.

Electric shutters aren’t the only familiar sight from holidays in southern Europe—air conditioning is another. However, Dr Mohareb, who specialises in sustainable urban systems, argues that widespread air conditioning is not the answer for the UK.

“While we do have the occasional extreme heat event, many days of the year we won’t have any need for air conditioning,” he said.

“When you’ve got very short intermittent heat events then the expense of it isn’t really worth it.”

Heatwaves pose a serious health risk, particularly for older people and those with existing medical conditions. A new report from the UK Green Building Council warns that, in a world where global temperatures rise by 2°C, parts of London and the South could experience heatwave conditions for up to 10 weeks each year.

Already, the toll is being felt. Research from Imperial College London estimates that more than 550 people may have died during the recent prolonged spell of hot weather.

Looking ahead, the Met Office’s latest three-month outlook suggests this summer (1 June to 31 August) is twice as likely to be hotter than average.

The urgency is clear. As our towns and cities face mounting pressure to adapt, Dr Mohareb says there is still time to respond—if we choose to act now.

”Adaptation is kind of the next big thing that we need to be moving on,” he said.

“We really need to be making more effort to improve the quality of the built environment so we’re better prepared for the extreme weather events we’re expecting.”

 

 

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