This petsafe extreme weather pet door is particularly reliable against both hot and cold weather thanks to its strongly insulated flap in the middle and its dual magnet system both inside and out during testing the petsafe extreme weather dog flap was found to have a lower heat transfer coefficient with a total value of 021 meaning that less heat is lost to put this into perspective the petsafe extreme weather dog flap loses up to 35 times less heat than standard closed dog flaps the h