After attending more than 240 incidents during the daytime today, Hertfordshire Fire and Rescue Service has declared a "major incident" amid record-breaking temperatures in the county.

A spokesperson for the fire service said crews have attended several major incidents, including large field fires and a road incident, throughout today (Tuesday, July 19).

Five appliances attended an earlier large vehicle fire on the M1 between Watford and Luton. In Rushden, near Baldock, six appliances attended a field fire, while a further six units extinguished a combine harvester fire in Hamels Lane, Buntingford.

In Codicote, near Welwyn, 12 firefighting appliances were summoned to another field fire.

The spokesperson urged residents to only phone 999 if a genuine emergency is in progress.

They said: "When you dial 999 to report an incident please be patient while our operators work to get to your call as quickly as possible.

"You can help to reduce the pressure on our staff by following our heatwave advice and staying safe over the next few hours."

In next-door London, the fire brigade has also declared a "major incident".

More than 60 firefighters were on the scene of an outbuilding blaze in Wembley, with more than 50 people evacuated from surrounding properties, according to London Fire Brigade.

In Wennington, in the London Borough of Havering, a terrace was gutted by a serious blaze which more than 100 firefighters attended.

Around 170 firefighters tackled a large grass fire next to the M25 at Pea Lane, Upminster, near the Dartford Crossing.

A fire next to the West Coast Main Line at Harrow impacted railway equipment, forcing a partial closure to the railway between London Euston and Watford Junction.

Pictures from Bedfordshire show a large blaze at Sandy, which broke out on Tuesday afternoon.

A spokesperson for Essex County Fire and Rescue Service said they received 110 calls to the control offices between 10am and midday today.

Neil Fenwick, from Essex, said: "On the hottest day we've ever seen in Essex, we're seeing a large number of calls across the county.

"At this time, please help us to help you - please only call 999 in a genuine emergency.

"Please don't have any fires like bonfires, campfires and avoid barbecues while the ground is so dry.

"If you're a smoker, please dispose of your smoking materials safely and responsibly."

Over the past three days, crews in Essex have attended several blazes along the Hertfordshire border.

Among them were a field fire near the M11 on Sunday, July 17, which spread to a disused station building at Great Chesterford, near Saffron Walden.

Crews from Harlow, Newport and Stansted extinguished a combine harvester fire in Mallows Green Road, Manuden, near Bishop's Stortford. The call came in at 12.57pm today.

The spate of fires follows record-breaking temperatures recorded throughout the UK.

Provisional Met Office data shows highs of 40.2C a London Heathrow Airport at 12.50pm, just 10 miles from the Hertfordshire border at Maple Cross.

The highest reading was seen at RAF Coningsby, Lincolnshire, where the mercury hit 40.3C.

The previous record stood at 38.7C, recorded at Cambridge University Botanic Gardens in 2019.