5 things that help you stock a winter car breakdown kit

Emergency foil blankets are sold everywhere and trusted by almost no one who has actually used one in a car. The mechanism is the problem: they only reflect radiated heat, which means they need existing body heat to bounce back at you. If you are already cold and the car interior is cold, there is very little heat to reflect. A wool or synthetic fleece blanket traps air around your body and retains warmth passively — from the moment you unfold it, without needing you to already be warm. A stalled car with the engine off will drop to near-ambient temperature within 30 to 45 minutes in January. A foil sheet slows that slightly; a decent blanket genuinely holds it.

Jump leads are fine if another car stops for you — but on a dark winter road at 10pm, that can mean waiting an hour for someone generous enough to pull over. A compact lithium jump pack lets you start the car yourself without a donor vehicle. The cold is what makes this a winter-specific item: low temperatures reduce a car battery's effective capacity by around 35 percent, which is why a battery that starts fine in October can refuse flatly in January. The lithium chemistry in a jump pack holds its own charge for six to twelve months sitting in a cold boot — the thing that killed older lead-acid booster packs. Most units also have a USB output, so if the battery has died and the phone is low, you can charge both problems at once.

Most winter breakdowns are not mechanical failures — they are a car that has slid onto a soft verge, cannot pull out of a snowy car park, or has a wheel spinning helplessly on compacted ice. Traction mats (short textured strips, sometimes sold as recovery tracks) give the tyre something to bite on for the two or three rotations needed to get clear. The non-obvious part is placement: the mats go in front of the drive wheels, not under the wheel that is currently spinning. You need them where the tyre will roll onto them as the car moves forward, not where it is sitting right now. Flooring it will fling them across the car park; driving slowly onto them is what actually works.

When the car breaks down in winter, your phone is doing serious work: calling the breakdown service, running maps, keeping you on hold, keeping you company. It will drain faster than you expect — cold temperatures noticeably reduce lithium battery output, and a phone at 30 percent in 0°C air can hit empty before the truck arrives. The problem with the power bank advice you have already heard is the word 'dedicated'. The one that travels between your bag and the car will always be empty when you need it. A power bank that lives permanently in the glovebox and is charged monthly is a different object with a different reliability record.

A dead or low battery is the most common phone problem in a breakdown, and signal dropout is the second — both are more likely in exactly the conditions where you need navigation most: cold weather, remote roads, snowstorm. Google Maps and Apple Maps both allow you to download regions for offline use; the download is free and works from that point on without any data signal. The part people miss is that offline maps still use the phone's GPS chip, which works independently of mobile signal. This means you can give accurate location information to a breakdown service or the emergency services even when you have no bars — which is genuinely useful when you are describing which layby on which road you are stuck on.