Science Focus - the home of BBC Science Focus Magazine
Dogs: 'Potentially dangerous temperatures' in cars all year round © Getty Images

Dogs: 'Potentially dangerous temperatures' in cars all year round

Published: 10th July, 2020 at 11:00
Subscribe to BBC Science Focus Magazine and get 6 issues for just £9.99

Temperatures inside cars can reach 25°C even in winter months, enough to cause overheating in breeds with flat faces.

Leaving dogs in parked cars can be potentially dangerous all year round, even in the winter when outside temperatures are low, researchers have warned.


A study by experts in dog welfare at Nottingham Trent University has found temperatures inside cars are hot enough throughout the year to pose a risk to dog health. The researchers monitored internal temperatures of cars in the UK, which had no dogs inside, every day for two years.

They found temperatures exceeded 25°C in every month of the year, high enough to cause overheating in breeds with flat faces, such as bulldogs and pugs. Most dogs are comfortable at temperatures between 15-25°C, but this is dependent on breed, coat length, fitness and a range of other factors, the researchers said.

Read more about dogs:

The team also found the highest internal temperatures in vehicles occurred between 4-5pm, and exceeded 35°C between April and September.

Dogs need to pant to control their body heat if temperatures exceed 35°C. However, in enclosed vehicles, panting can be harder for dogs due to humidity and lack of air movement, resulting in reduced latent heat exchange.

Along with panting, signs of heat stoke in dogs include red or dark gums and tongue, confusion and unsteadiness, diarrhoea, vomiting and agitation. If left untreated, heatstroke can be fatal for dogs.

Dogs can struggle to cool down in cars, where it is often humid with little air flow © Getty Images
Dogs can struggle to cool down in enclosed cars, where it is often humid with little air flow © Getty Images

Based on their findings, recently published in the Open Veterinary Journal, the researchers suggest annual campaigns to raise awareness of the risk of dogs becoming ill in hot cars, which usually begin in May, need to start earlier in the year.

Dr Anne Carter, a researcher at Nottingham Trent University’s School of Animal, Rural and Environmental Sciences, and first author on the study, said: “Our work shows an even bigger risk to leaving dogs in parked vehicles than previously thought.”


She added: “People assume the risk is only midday during the summer, when in fact cars can reach potentially dangerous temperatures all year round, with late afternoon the hottest time period.”

Reader Q&A: Why does my dog go round in circles before she poos?

Asked by: Chris McMullon, Barnham, West Sussex

A 2015 study in the Czech Republic and Germany reported that dogs tend to poo along the north-south axis of the Earth’s magnetic field. This presents the intriguing possibility that the circling behaviour is their way of gauging the orientation of the magnetic field before they get down to business.

But this research is controversial, and other researchers have been unable to reproduce the findings. It’s more likely that dogs are acting out an ancestral behaviour to flatten the grass and drive away insects before they squat.

Read more:


Sara RigbyOnline staff writer, BBC Science Focus

Sara is the online staff writer at BBC Science Focus. She has an MPhys in mathematical physics and loves all things space, dinosaurs and dogs.


Sponsored content