If you having to make errands while your taking your ferrets to the vets office
Remember heat KILLS!
Do not under any circumstances leave your ferret in the car if you cant take them with you take them home! Rolling down windows, putting ice packs or battery fans on carriers do not protect your ferrets from the heat that builds up inside your car.
It only takes minutes for a ferret left in a car on a warm day to have heatstroke and die. Most people dont realize how hot it can be in a car on a hot day.
However, on a 78 degree day, temperatures in a car parked in the shade can exceed 90 degrees -- and hit a scorching 160 degrees if parked in the sun!
Many experts recommend not to leave any pet or child in parked cars even for short periods if the temperature is in the 60s or higher.