Extreme heat is a killer, even in Britain – and it’s going to get worse

Heatwaves are the deadliest extreme weather event in the UK, and are set to become more frequent and more intense

The map shows the predicted air temperatures across Europe on Sunday 17 July. The light pink within the bright pink is between 40 and 44 degrees Celsius. (2022 European Centre for Medium-Range Weather Forecasts (ECMWF))

Extreme heat is a killer, even in the UK. While the hot weather baking Britain this week is enjoyed by many, it is also likely to silently kill hundreds, experts warn.

Highs of 33 degrees Celsius are expected in some areas on Monday afternoon, which would make it the hottest day of the year so far. And it’s only expected to get hotter; the Met Office on Monday issued a rare extreme heat warning for much of England and Wales, starting on Sunday 17 July and lasting into early next week.

The Met Office has already issued a level three heat-health alert from 9am on Monday to 9am on Friday in the east and south-east of England, warning people to look out for others especially older people, young children and those with health conditions.

Heatwaves are the deadliest extreme weather event in the UK, and in England there are on average 2,000 heat-related deaths every year, according to the Met Office.

Read latest updates: UK extreme heat - live

Climate scientists warn they are only set to get worse and more frequent as the world pumps out more greenhouse gases into the atmosphere. In March, the Met Office raised the bar for what is considered a heatwave in parts of the UK to reflect the country’s warming climate.

Friederike Otto, who leads The World Weather Attribution, an effort by climate scientists to attribute the extent to which climate change is influencing extreme weather events, says every heatwave the world experiences today has been made more intense and more likely due to climate change.

“In 2020, in the UK alone more than 2,500 people died because of hot days – and those were less hot and less frequent than what we are already seeing this year,” she said.

The latest hot weather comes amid a Conservative leadership contest in which some candidates have questioned the government’s commitment to reach net zero emissions by 2050.

“Hundreds of people will die in the UK over the coming week due to the hot weather,” said Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics on Twitter. “Tory candidates to be the next PM who want to slow down action to reach net zero emissions are implicitly arguing that we should allow heatwaves to grow even more intense and frequent.”

The main health risks posed by heat are dehydration, overheating  - which can make symptoms worse for those who suffer from cardiovascular conditions or struggle to breathe, as well as heat exhaustion and heatstroke which can be deadly.

In every heatwave excess mortality rates increase, with the largest number of deaths observed among the elderly because of underlying medical conditions, said Marina Romanello, director of the Lancet Countdown, which tracks and works to advance progress on health and climate change.

Dr Romanello told The Independent those elderly people who lived on their own were particularly vulnerable as are children under the age of one because they don’t thermoregulate well, she said.

“They are at really high risk from the extreme temperatures,” she said, of young babies. “Don’t expose them to the high temperatures, and don’t expose them obviously to the sun and keep them very well hydrated.”

Pregnant women, those with health conditions such as heart or lung problems, and those who work outside are also seen to be at higher risk from the heat, experts said.

Research by academics at the University of Reading, University College London and the Met Office has found that heat-related mortality is predicted to increase in England and Wales with further global heating. They found a 42 per cent increase in mortality risk during summer heat extremes is expected by 2 degrees Celsius global warming.

The average global temperature has already increased by at least 1.1 degrees Celsius since the 1880s.

Experts have warned that increases in heat-related deaths will strain the NHS and put pressure on the economy as productivity declines as people are unable to work or need more breaks.

“We’re not really geared up to deal with more frequent heatwaves, other than through enacting emergency plans, and we can’t really run in crisis mode each and every summer,” said Prof Nigel Arnell of the Department of Meteorology at the University of Reading. “We urgently need to improve our existing housing stock to better insulate against both hot and cold weather – and that will help reduce our exposure to rising energy bills too.”

The government has estimated that one in five homes are likely to overheat even during a relatively cool summer. Even during cooler summers this can make sleeping difficult.

Tips to keep cool include hydrating, staying indoors, wearing light clothing, using fans or air conditioning, shutting curtains to stop the sun getting in and heating the house, and maintaining ventilation in homes, experts said.