As Britain basks in summer heat, danger lies behind closed car doors - and it could cost lives.

Dogs left in hot vehicles can suffer fatal heatstroke in minutes, yet many well-meaning members of the public don't realise that breaking into a car to save them could land them in court.

Now a UK lawyer is warning both pet owners and would-be rescuers to understand the law before taking action.

"It's not technically illegal to leave a pet in a car," says Daniel McAfee, Head of Legal Operations at legal platform Lawhive.

"But the Animal Welfare Act 2006 makes owners criminally responsible for their animal's welfare. If a pet becomes ill, suffers, or dies due to heat exposure, owners can face animal cruelty charges carrying prison sentences and unlimited fines."

It's not just pet owners who need to tread carefully. While the public might assume they're protected if they act to save a distressed animal, McAfee is quick to clarify that there are crucial legal steps to follow to avoid facing criminal damage charges.

"While the police do have powers to intervene under various circumstances [including responding to emergency calls about animals in distress], the law also provides defences for members of the public who break into cars to rescue animals," he explains.

This protection, often called the "lawful excuse" defence, comes under Section 5(2)(b) of the Criminal Damage Act 1971. But it only applies if the person genuinely believed that immediate action was necessary to protect the animal from serious harm or death.

"One common misconception is that acting out of compassion alone is a legal defence - it is not," McAfee warns. "The courts will look for a demonstrable and reasonable belief that immediate action was necessary to protect the animal's welfare, in accordance with Section 5(2)(b) of the Criminal Damage Act 1971."

To avoid legal trouble, members of the public are urged to take several key steps before intervening: "There are several steps a member of the public should take to protect themselves legally before acting," McAfee advises. "These include contacting the police immediately, taking photographic or video evidence of the animal in distress, and attempting to locate the vehicle's owner nearby."

Crucially, dogs and other pets are considered property under English and Welsh law - which is why damaging a car, even in the name of rescue, could be prosecuted unless the court agrees the action was reasonable.

Courts assess each case individually, weighing factors like temperature conditions, the apparent urgency of the situation, and how long the animal appeared to be in distress.

With internal temperatures in parked vehicles able to rocket to 47°C in under an hour - even when it's just 22°C outside - the dangers are real, and RSPCA reports of animals left in cars spike each summer.

So while compassion is commendable, legal awareness is essential.

If you see a dog in distress in a locked car, don't just act - document, alert, and proceed wisely.