Tesco has joined forces with the RSPCA to ensure dogs stay safe as temperatures soar to above 31C across the UK.
Staff are patrolling car parks to check customers don’t leave pets in vehicles.
They have also been trained to recognise the signs of heatstroke and help animals suffering from it.
The initiative has been set up across Birmingham, throughout the wider West Midlands, and some other spots in England.
It came in time for England and Wales to be hit with the hottest day of the year on Sunday.
Temperatures above 20C put dogs at risk, with them having a 50-50 chance of survival if they catch heatstroke.
Owners should never leave dogs locked in cars on warm days – even if the windows are open and the vehicle is parked in the shade, the RSPCA says.
A recent warning from the charity said: ‘A car can become as hot as an oven very quickly, even when it doesn’t feel that warm.
‘When it’s 22 degrees, in a car it can reach an unbearable 47 degrees within the hour.’
The British heatwave is showing no sign of slowing down as the Met Office says it could get even hotter this week.
Signs of heatstroke in dogs include heavy panting and excessive drooling.
They may appear lethargic, drowsy or uncoordinated, or collapse and vomit in extreme circumstances.
The RSPCA advises people to dial 999 immediately if an animal stuck in a car is displaying symptoms.
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