The heatwave health alert issued by Public Health England has been extended to Friday as much of the country continues to swelter under high temperatures. Experts said the heatwaves in the summer of 2020 caused more than 2,500 premature deaths and that the climate crisis is making heatwaves more intense and more frequent. PHE’s level 3 heat-health alert requires social and healthcare services to take specific action to protect high-risk groups, such as older people, children and babies. The Met Office issued its first ever extreme heat warning for the UK on Monday. “Everybody can be affected by high temperatures and most people are aware of good health advice for coping with hot weather,” said Dr Owen Landeg at PHE. “However, it’s important to keep checking on those who are most vulnerable such as older people and those with heart or lung conditions.” Among the advice from PHE is to stay cool indoors, closing curtains on rooms that face the sun, drink plenty of water and avoid excess alcohol, and walk in the shade, use sunscreen and wear a wide-brimmed hat, if you have to go out. Steven Ramsdale at the Met Office said: “High temperatures are going to continue through a large part of this week, with temperatures regularly in the high-20s and low-30s celsius by day, along with high overnight temperatures. “Many areas of the UK will continue to reach heatwave thresholds, and whilst the highest temperatures are likely to be in central and southern parts of the UK, some of the most unusually high temperatures are likely to be seen over parts of the west, particularly over Northern Ireland. Temperatures should fall for most areas into the weekend.” Climate extremes expert Vikki Thompson at the University of Bristol said: “Heatwaves can have devastating impacts on human health. In the summer of 2020 heatwaves led to an estimated total excess mortality of 2,556. Hot weather causes deaths due to cardio and respiratory problems caused by increased strain on the heart and lungs. “Heatwaves are one of the weather extremes that are most easily linked to climate change, which is already affecting us here in the UK,” said Rob Thompson, a meteorologist at the University of Reading. “British heatwaves are already hotter and last longer, compared to just a few decades ago. We can expect that extreme summer heatwaves of the type that can kill people in the UK will become a regular occurrence.” Climate scientist Michael Byrne at the University of St Andrews said: “[The heat warnings are] a stark reminder of the dangerous and accelerating impacts of global warming. Extreme heat is a severe threat to public health that – as pointed out by the Climate Change Committee only last month – the UK is woefully underprepared to deal with.”