Police had to smash their way into a car in Bath yesterday after a dog was left in a car in temperatures heading for 30C.

Dog owners are being reminded of the dangers of locking their pets in cars during hot weather following two incidents which saw police having to smash car windows to rescue animals in distress.

One occurred at 9.30am yesterday in Lansdown Lane when a dog had to set free from a vehicle once temperatures started to rise quickly, while the other happened earlier in the month at Bathampton, where a couple had left a dog in the boot of their car while on a boat ride.

Police have warned that dogs can die from heatstroke in as little as 20 minutes.

PC Karen Hoyle said in warm, sunny weather, cars became like ovens and even if on cloudy days, the temperature inside a car can still be dangerously hot for a dog.

She warned that leaving car windows open or putting a bowl of water inside did not help.

She said: "The owners were caught out by leaving their dogs in the car when the weather was cool – but then it suddenly warmed up when they were away."

Police say leaving car windows open or putting a bowl of water inside a car does not help.

PC Hoyle added: "Owners who put an animal at risk by leaving it locked inside a car can face prosecution."

The RSPCA advises that animals should never be left inside cars.