West Midlands weather: Police warning as nation sweats on hottest day of the year

Temperatures reached 32.2C (89.9F) at Brize Norton on Tuesday afternoon, the Met Office said, with the mercury predicted to reach 35C (95F) by the end of the day - making it hotter than Barcelona.

In Wolverhampton and Staffordshire, the temperature was set to peak at 31C (87.8F) at around 4pm, while some parts of the West Midlands could reach 34C (93.2F).

• MORE: Send us your summer snaps for the chance to win £100!

• MORE: Tettenhall Pool reopens after algae and fly larvae break out

Staffordshire Police warned people not to cool off in open water after a man got into difficulty in a canal and died on Monday.

The 46-year-old got into trouble after jumping into the canal on Waterside Road, Burton-on-Trent, at around 10pm. He was pulled out of the water and treated by paramedics but later died at the town's Queens Hospital.

Chief Inspector Steve Maskrey warned the public to stay away from canals, rivers and lakes and to only use supervised swimming pools.

Meanwhile Tettenhall Pool in Wolverhampton was closed for much of the day because of an algae and fly larvae break out.

As the city sweated, the popular facility remained shut for public safety reasons until council workers finished clearing the water in the early afternoon.

Further south, train services in and out of one of London's busiest stations were delayed after heat-related speed restrictions were brought in.

The capital's ambulance service said it had had 300 more calls than usual and the RSPCA said it had also seen a spike in calls from members of the public concerned about dogs left in hot cars, conservatories, sheds and caravans.

The Met Office has declared a Level 3 heatwave alert and Public Health England was urging people to take care.

However, the Met Office warned that the heatwave was soon likely to be replaced by heavy rain and thunderstorms, issuing a yellow alert for rain for much of the country.

Dr Angie Bone, head of extreme events at Public Health England, said: "Older people, those with underlying health conditions and young children may all feel the ill-effects of heat over the coming days."

Trains in an out of Paddington station in London are due to be affected until late this evening because of the heat.

The National Rail Enquiries website said that services on the Great Western Railway, Heathrow Connect, and Heathrow Express would be subject to delays and cancellations until 10pm because of "speed restrictions due to high temperatures".

London Ambulance Service's medical director Dr Fenella Wrigley said: "We see an increase in calls because people forget to stay hydrated and the heat can exacerbate heart and breathing conditions."

The RSPCA has also seen a spike in calls from members of the public concerned about dogs left in hot cars, conservatories, sheds and caravans.

Inspector Justin Stubbs said three dogs had already died this summer after being left in cars.

Gorillas at London Zoo were helped to deal with the heat by keepers who fed them fruit tea ice blocks.

Air pollution is also set to reach dangerous levels, according to ClientEarth.

Alan Andrews, lawyer for the environment consultant, said the "spike" in pollution caused by high ozone levels was "bad news" for Western Europe and those who suffer from respiratory illnesses.

But London's Ice Bar was experiencing more punters than normal trying to get out of the heat.

Tom Hunter, head of marketing, said he was expecting large numbers to visit the bar - which is kept at minus 5C (23F) - to avoid the heat outside.

The Met Office said that 31.2C (88F) was recorded at Porthmadog in north Wales and 26.2C (79F) at Castlederg in Northern Ireland, the hottest temperatures of the year in those countries.

Met Office forecaster Alex Burkill said temperatures were likely to peak in the North West, London and Oxford.

He added: "It's not going to be the hottest day for too far back - we reached 36.7C (98F) on July 1 last year so it will be the hottest day for over a year, but not the hottest July day ever."

But the good weather is not here to stay. The Met Office has issued a yellow weather warning for severe thunderstorms, large hail and strong winds which could lead to flash flooding of homes, businesses and transport networks.

The forecaster added there is a risk of thunderstorms "coming across from Northern Ireland later on this evening, and then spreading across Scotland and then also further south across Wales and northern England, and also western parts of England - a big chunk of the UK - as we go through tonight and into tomorrow".