Drivers warned not to leave dogs in cars tomorrow, as hottest day approaches, their cars will become a 51-degree furnace (124°F) in just 20 minutes

  • As temperatures are expected to reach in excess 35 degrees tomorrow, Direct Line warns to keep dogs out of unbearably hot cars
  • A fifth (19 per cent) of dogs have suffered from heatstroke
  • In 35 degrees heat, the inside of a car can reach 51 degrees in just 20 minutes
  • The majority (79 per cent) of owners have never thought to use sun cream on their pets, but it is strongly recommended for short haired dogs
  • Even in the evenings, 21 degrees outside can turn into 40 degrees inside a car in just 30 minutes

As temperatures are set to reach highs of over 35 degrees Celsius in some parts of the UK tomorrow, Direct Line is reminding owners not to leave their pets in parked vehicles and take extra precautions in the hot weather.  Dogs need plenty of fresh air and water during the heat and should not be left unattended in parked cars. Research1 has revealed that nearly a fifth (19 per cent) of dogs have suffered from heatstroke.

Research from San Francisco State University2 found that when the outside air temperature is 35 degrees Celsius, the inside of a car can heat up to 45 degrees within just 10 minutes and 54 degrees in 30 minutes. This can be catastrophic for dogs who are at risk of heatstroke, and in some cases, this can be fatal.

Even when the sun goes down, drivers should take extra care as when the temperature is a much lower 21 degrees, the inside of a car can heat up to above 40 degrees in just half an hour.

Table one: Estimated Vehicle Interior Air Temperature vs Elapsed Time

Elapsed time

Outside Air Temperature C (F)

21 (70)

24 (75)

26 (80)

29 (85)

32 (90)

35 (95)



10 minutes


31 (89)

34 (94)

37 (99)

40 (104)

42 (109)

45 (114)


20 minutes


37 (99)

40 (104)

42 (109)

45 (114)

48 (119)

51 (124)


30 minutes


40 (104)

42 (109)

45 (114)

48 (119)

51 (124)

54 (129)


40 minutes


42 (108)

45 (113)

47 (118)

50 (123)


56 (133)


50 minutes


44 (111)

46 (116)

49 (121)

52 (126)

55 (131)

58 (136)


60 minutes


45 (113)

47 (118)

50 (123)

53 (128)

56 (133)

59 (138)


Over 1 hour


46 (115)

49 (120)

51 (125)

54 (130)

57 (135)

60 (140)


Source: Department of Geosciences, San Francisco State University2

As the nation basks in glorious sunshine this week, pet owners are also being advised to consider the risk of their pet suffering from sun burn.  The majority of dog owners (79 per cent) have never put sun cream on their pet, even during soaring temperatures. Direct Line Pet Insurance recommends dog owners, especially those with short haired dogs, regularly apply dog friendly sun cream to their pets during hot weather and keep them out of direct sunlight. Even though most dogs have fur, their skin can be incredibly sensitive and need some extra protection against potentially harmful ultraviolet rays. 

Madeleine Pike, Veterinary Nurse at Direct Line, said: “With this hot weather hitting the UK, it is important to remember that leaving your dog in the car whilst popping to the shops could have potentially fatal consequences, or at least cause extreme discomfort to your pet. Cars heat up incredibly fast; when the temperature outside is over 35 degrees Celsius the car can reach 51 degrees Celsius inside within just 20 minutes, so under no circumstances should pets be left in the car.

“Pet owners also need to remain vigilant when out and about and consider when they may need to introduce sun protection. Short haired dogs have ultra-sensitive skin which is often more susceptible to burning or causing the animal to suffer from heatstroke. To help prevent this, owners should apply sun cream to their dogs regularly for extra protection in warm weather, keep them hydrated and in a well-ventilated space and keep them out of direct sunlight when possible. Carrying fresh water with you at all times when out with your dog is also essential.

“Limiting the duration and intensity of exercise during warmer days will also help to combat the effects of heatstroke and overheating. Symptoms of heatstroke in dogs include excessive panting, drooling and lethargy.”

Direct Line’s tips for keeping your dog safe this summer:

  • Do not leave your dog in a parked car for any length of time as the car will heat up very quickly
  • Limit the duration and intensity of your dog’s exercise
  • Exercise early in the morning or later in the evening when the temperatures are cooler
  • Apply dog friendly sun cream to dogs, especially those with short hair
  • Keep your animal in the shade when the temperatures are at their highest
  • Always keep a fresh water supply with you for your dog when going out in the heat to ensure they remain hydrated
  • Check the ground is not too warm before your dog walks on it – if the back of your hand can’t stay on the concrete for at least five seconds due to the heat then it is too warm for your dog


Notes to Editors

Research carried out by Petbuzz Market Research amongst 1,390 UK pet owners


For further information please contact:

Olivia Thwaites

Direct Line

[email protected]

01651 343 2145


Direct Line

Started in 1985, Direct Line became the first UK insurance company to use the telephone as its main channel of communication. It provides motor, home, travel and pet insurance cover direct to customers by phone or on-line.

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