Home › Guides › Keeping Vials Cold on a Road Trip
Keeping Vials Cold on a Road Trip
A car passes 50 °C in an hour in the sun. Three ways to keep vials cold by trip length, the two car mistakes, and border crossings.
Last reviewed · written by PepPrep · not medical advice
A car is the hardest place to keep anything cold: a parked car in the sun passes 50 °C in an hour, and the boot is worse than the cabin. The good news is that a car also has a power socket, which opens up options a plane does not.
Three ways, by trip length
- A day: an insulated cooler with frozen packs, packed as in the packing guide, on the back seat footwell out of the sun. Nothing else needed.
- Two or three days with hotels: the same cooler plus a plan for the packs. Hotel minibars are 10–14 °C and do not freeze anything; a evaporative wallet needs only a tap and re-sets overnight. Ask reception about a freezer; most have one.
- A week, several people, or no hotels: a compressor car fridge on the 12 V socket holds a set temperature and runs off mains at night. It is the one time that product earns its price.
The two car mistakes
Leaving the cooler in the car overnight (the car cools, then it heats fast at dawn), and putting it in the boot, which has no air conditioning and sits over the exhaust. Cabin floor, behind the front seats, with the seat belt through the handle.
Border crossings
Driving across a border with supplies is usually simpler than flying, but the same rules apply: keep the product in its labelled packaging, carry any paperwork you have, and do not argue with an officer about what a vial is. The country pages linked from the flying guide cover the US, Canada, the UK, the EU and Australia and apply at land borders too.
Proof
A temperature logger in the cooler is the only way to know what happened during the four hours you were driving. It costs less than one replacement vial.
Supplies mentioned: Travel & Cooling · Travel checklist