Extreme heat partially shuts schools
David Jones/PA WireSome schools are set to partially close to pupils and staff due to "extreme heat".
Temperatures across parts of Devon and Cornwall are set to rise above 30C (86F) and the UK Health Security Agency (UKHSA) has issued a red heat health alert for the South West, which will be in force between 01:00 BST on Wednesday and 23:00 on Thursday.
Due to rising temperatures, a number of schools and nurseries across Devon and Cornwall and the Channel Islands are partially closed, or planning closures later in the week, or letting parents decide if their children should go in.
Paul Aked, head of meteorology at Jersey Met said, temperatures across both Channel Islands were "potentially record-breaking".
Bryher/BBC Weather Watchers"The hottest temperature we've recorded officially in Jersey is 37.9C [100.2F]. We could see that record being broken. The records of Guernsey are slightly lower," Aked said.
He said a maximum temperature of 36C (97F) was forecast for Guernsey.
Beaulieu Convent School in Jersey said classes were open but it had sent an email to parents saying it was their decision over whether they wanted their children to go in and Busy Bees Nursery on the island is closing its baby room.
Cath/BBC Weather WatchersA Met Office amber extreme heat warning has been issued across parts of the region on Tuesday, covering all of Devon on Wednesday through to midnight on Thursday.
BBC broadcast meteorologist Linda Ludlow said Cardinham, in Cornwall, near Bodmin, was the "warmest UK observation at 27C [81F]" at 08:00, adding Devon could reach 33C (91F).
"The far east of Devon is under the Met Office extreme heat warning today, extending to include all of Devon and east Cornwall from midnight tonight until Thursday evening," she said.
In Cornwall, a Severe Weather Emergency Protocol has been activated to support people sleeping rough.
Cornwall Council said teams would carry out additional welfare checks, offering bottled water and sun protection.
Schools shut early
According to Devon County Council's website, several schools, including Clyst Vale Community College, Ottery St Mary Primary School and The Park Community School, were being partially shut between Tuesday and Thursday.
In a post on social media, Kingsbridge Community College said students would be allowed to wear PE kits instead of uniforms to ensure "comfort and wellbeing of all students".
Tiverton High School, among others, closed at 12:30 "for extreme heat", the county council said.
Some schools have also said they will close at 12:30 on Wednesday and Thursday.
In Guernsey, Castel Primary School said its pupils were "not required" to wear uniform for the rest of the week, instead they were allowed to wear "light, sensible" clothing.
It said it would also introduce a "no hat, no play" policy and those without a hat would not be allowed out in the sun.
What about water?
Periods of very hot weather puts real pressure on our water resources, but South West Water said it was "well prepared for the warmer months".
The utility has advised people to be careful with water and to take steps such as shorter showers.
Reservoir levels across Devon and Cornwall are currently at about 82%, which is above where they were at the same point in 2022, when a hosepipe ban was implemented.
Guernsey Water is encouraging people to "use water wisely", adding the average summer demand was about 13.5 million litres per day, which rose to about 15 million litres per day during the previous heatwave.
Operations manager Jon Holt said: "Simple, sensible actions taken by thousands of customers can overall make a real difference, ensuring that the reduction in storage levels is as low as possible."
For farmers, hot summers can pile on the pressure too, according to the National Farmers Union.
There was the impact on livestock, crop and vegetable yields, but also issues such as protecting workers against heatstroke, it said.
For wildlife, lower river flow levels could hit aquatic insects and fish, said the Devon Wildlife Trust.
The charity also said warmer temperatures increased the risk of harmful algal blooms in waterways.
Finally, the charity added putting out water - including at ground level in a shallow dish - could help small mammals such as hedgehogs that may be struggling during a heatwave.
Great Western Railway (GWR) and South Western Railway (SWR) have warned train passengers to only travel if necessary on Wednesday and Thursday.
GWR warned extreme heat could cause rails to expand and buckle, so, when temperatures reached certain thresholds, trains must run more slowly to keep services safe.
"This will mean fewer trains and slightly longer journey times during the warmest periods of each day," it said.