How long can you leave milk in car if it is 29 degress out?

If the temperature outside is 29°F (-1.7°C), milk should ideally be kept in the car for no more than 2 hours. While the cold temperature can help keep the milk from spoiling, it's important to note that temperatures can fluctuate inside a car, especially if the sun is shining. To ensure safety and prevent bacterial growth, it's best to refrigerate milk as soon as possible.