As Britain sweltered through the country’s hottest day on record last month, supermarket delivery vans wove around the streets as usual delivering shopping to people’s homes. But while the vans have technology to keep the food and drink chilled in the back, a surprising number don’t provide the same service to the humans in the front.

Sainsbury’s, for example, confirmed to me its vans don’t have air conditioning in the cabs. The supermarket chain said it gave drivers more frequent breaks, access to cold drinks and a relaxed dress code during the heatwave.

Tesco’s older vans don’t have air conditioning either, though its new electric ones do. The company said drivers without air conditioning were “able to stay safe and comfortable with ventilation, regular breaks and plenty of water”. Ocado told me three-quarters of its fleet has air conditioning and that will soon rise to 90 per cent. Waitrose, meanwhile, has air conditioning in all its vans.