Park-goers have been warned by a London council to avoid sitting under trees over health and safety concerns.
Harrow Council, in the capital's northwest, has warned locals of "sudden branch drop syndrome" - forcing them out into the sun despite the heatwave.
No injuries have so far been reported, and there is no known cause for the "syndrome".
The council said the branches dropped in the borough's parks during the June heatwave.
The local authority has warned locals of 'sudden branch drop syndrome'
PA
"Tree branches can break off and fall to the ground unexpectedly," a statement from the authority says.
"It typically occurs during warm weather."
"Our qualified tree officers carry out regular inspections of parks trees and highway trees," the council added.
MORE LONDON COUNCIL MADNESS:
'Tree branches can break off and fall to the ground unexpectedly,' Harrow Council said (file photo)
PA
"Any necessary work for public safety is issued to our tree contractors."
The council has also told residents to avoid "sitting, playing or gathering under large trees in the park".
While the council doesn't manage trees on private or unregistered land, it outlined how it had been keeping tabs on those sitting near streets and pathways, parks and open spaces, allotments and woodlands and at cemeteries.
"We prune shrubs and trees on a regular basis," the council said.
"This ensures our parks and paths meet health and safety standards."
The tree warning comes as Britain braces for record-breaking heat - with an amber heat alert issued by the UKHSA
UKHSAThe notice comes as Britain basks under record-breaking heat - with an amber heat alert issued by the UK Health Security Agency (UKHSA) across the south of England.
The UKHSA has put out two alerts - amber and yellow - which start from 12pm on Friday and end at 9am on Monday, July 14.
Meanwhile, the Met Office has hinted at "intense heat" building through the next 48 hours with widespread highs expected of 30Cs.
Western regions are in the firing line for the highest temperatures, with warm weather in parts expected into next week, meteorologist Honor Criswick said.