June heatwave in UK led to ‘mass sleep deprivation’, poll suggests

Exclusive: Record temperatures fuelled by climate crisis left 86% of homes ‘too hot’ and many people feeling unwell

With parts of England once again in the grip of a heatwave, an opinion poll shows the one at the end of June led to “mass sleep deprivation”, with two in three people struggling to sleep during the sweltering nights.

Almost half of people said they had lost at least three hours of sleep each night. The results are consistent with scientific research showing that global heating is damaging sleep across the world.

The recent record-breaking heatwave would have been impossible without the fossil fuel burning that is driving the climate crisis, and the poll shows the effects global heating is already having on people.

The third heatwave of the summer will arrive this week, the Met Office said on Monday, posing a further threat to lives and livelihoods. Parts of southern England are likely to have highs of about 32C on Tuesday to 34C on Thursday, with 35C predicted for isolated areas on Friday and Saturday, according to the forecaster.

The vast majority of people in the UK (86%) said their homes were too hot during the June heatwave and a quarter said they or someone in their house had felt physically unwell as a result. About one in five cancelled plans due to the high temperatures, while one in five also had to throw away food that went off or could not be kept cool.

The heatwave will have caused hundreds or thousands of early deaths, but the statistical analysis required to determine the number takes time to complete. The UK Health Security Agency has previously found that more than 10,000 people died due to summer heatwaves between 2020 and 2024.

In the new poll, conducted by YouGov for Greenpeace, more that half of respondents said their homes needed retrofit upgrades to cope with future heatwaves, but 78% said they would struggle to afford them. Almost half of people said they would support a levy on highly polluting companies to fund these essential upgrades, by far the most popular option. The next most popular was reducing public spending in other areas. Only 5% supported raising personal taxes to fix the UK’s inadequate infrastructure.

The government’s official adviser, the Climate Change Committee, has warned for more than a decade that the UK’s plans to protect people from rapidly worsening extreme weather are inadequate. In May, the CCC said the UK was “built for a climate that no longer exists” and needed urgent changes to survive global heating.

During the late June heatwave, high monthly temperature records were shattered, with 37.7C recorded at Lingwood, Norfolk , along with record-breaking overnight minimums – so-called tropical nights – of 23.5C in Wales and 23.2C in England.

“The poll exposes the brutal reality of dragging our feet on climate action in the UK, such as mass sleep deprivation,” said Mel Evans, head of climate at Greenpeace UK. “Heatwaves are now a creeping health, housing and economic emergency that is costing families money they don’t have. And as these extremes become our new normal, the public wants the corporate polluters who made this mess to pay their fair share towards fixing it.”

At the peak of the heatwave, Dr Hans Kluge, the World Health Organization’s director for Europe, said: “People are struggling to sleep, emergency rooms are filling up and ambulance services are breaking records. But prevention works. Heat-related deaths in Europe in 2023 would have been around 80% higher without the adaptation measures already in place. We need more of them [as] the summers ahead will be harder.”

Dr Laurence Wainwright at the University of Oxford said sleep was adversely affected during heatwaves: “When we have ‘tropical nights’ – where temperatures don’t fall below 20C – a good night’s sleep is all but impossible for most. The implications are significant: a drop in work performance, an increase in accidents, lower school test scores [and] a decline in mental health.”

The heatwave also hit businesses, with 60% of poll respondents saying their workplaces had been “too hot” and more than a quarter saying they had been less productive. Nearly one in 10 reported working in conditions they felt were unsafe. The CCC has recommended that the government should set a maximum temperature for indoor and outdoor working.

The YouGov poll involved 2135 adults in the UK surveyed between 30 June and 1 July 2026, with the figures weighted to be representative of all UK adults.