The Met Office has extended its extreme weather across much of England and Wales for another day.
Initially the rare amber alert was in place for Sunday, with forecasters predicting temperatures to exceed 40°C.
Yesterday it was extended to Monday, and now another day has been added on, with people being advised to stay indoors where possible.
The Met Office warns that not only the most vulnerable could suffer adverse health effects from the ‘extreme heat’.
Forecasters warn this could lead top to ‘potential serious illness or danger to life’. There could also be a ‘widespread impact’ on infrastructure like gas, electricity and water supplies.
The Met Office is advising people to stay indoors where possible and to drink plenty of water to help cope with the heat.
Parents are also being encouraged to limit their children’s exposure to the blistering sunshine.
Drivers have been told to expect delays as road surfaces are melted by the sun, while rail passengers can also expect disruption as the heat makes tracks ‘expand and buckle’.
Forecasters warn that ‘substantial’ changes to people’s working practices and daily routines will be needed to keep them safe.
It comes as the TUC calls for a maximum indoor working temperature of 30°C, 27°C for strenuous work – to indicate when workers should legally stop.
The union also wants companies to allow staff to come in earlier or stay later to ‘avoid the stifling and unpleasant conditions of the rush-hour commute’.
Dr Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, said: ‘Heat-health alerts have now been issued to the majority of the country, with temperatures set to remain consistently high throughout the duration of this week.
‘Most of us can enjoy the hot weather when it arrives, but it is important to keep yourself hydrated and to find shade where possible when UV rays are strongest, between 11am and 3pm.
‘If you have vulnerable family, friends and neighbours, make sure they are aware of how they can keep themselves protected from the warm weather.’
This week’s weather is a result of hot air flowing to the UK from Continental Europe.
Heatwaves have been made hotter, longer and more frequent by climate change, and experts have warned of the need to adapt homes and cities in the UK for a future of more intense – and deadly – summer heat.
Ambulance services are already on the highest level of alert as difficulties with the hot weather combine with Covid-19 absences among staff and ongoing delays handing patients over to A&E.
London Ambulance Service urged the public to support it as the heat continues by only calling 999 in the event of a life-threatening emergency, keeping hydrated and staying out of the sun during the hottest periods of the day.
The Royal Life Saving Society UK warned people about the dangers of trying to cool off in lakes, quarries, rivers and other waterways in the extremely hot weather.
Hot weather can put a strain on the heart and lungs, with older people, those with pre-existing health conditions and young children particularly at risk.
It can cause dehydration, heat exhaustion or even heatstroke, and affect the ability to work or concentrate.
People are being encouraged to try to keep their homes cool, for example by closing blinds or curtains and keeping bedrooms well ventilated at night, drink plenty of fluids, avoid too much exercise, and stay out of the sun during the hottest part of the day.
In some areas, the heatwave comes in the wake of months of below-average rainfall, and water companies are urging households to save water, as demand surges in the face of the high temperatures.
Get in touch with our news team by emailing us at webnews@metro.co.uk.
For more stories like this, check our news page.