Winter Emergency Kit for Your Car

Pack for the night you're stuck, not the morning commute

Most people pack for getting the car moving and forget about staying warm while waiting, which can take 2-6 hours in a storm. Plan for a full set of warm layers per regular passenger: a real wool or fleece blanket, a hat, gloves and dry socks. A thin foil blanket is a backup, not the main plan. The checklist quantities assume 2 regular occupants, so scale water, food, blankets and layer sets up or down to match yours.

Spend money on the portable jump starter and a metal-blade folding shovel, because those are the two items that actually get you home. Save money everywhere else. Take an old blanket, hoodie and boots from home, and use a cheap bag of non-clumping clay kitty litter (UK: cat litter) instead of branded traction grit.

Split the kit between the cabin and the trunk

A trunk (UK: boot) can freeze shut, sit under luggage, or get crushed in a rear-end collision. Keep the grab-first items in the cabin: scraper and brush, phone cable, flashlight (torch), a few hand warmers, and one blanket under a seat or behind it. Everything else goes in one lidded bin in the trunk, with the shovel and litter bag riding alongside. Inside the bin, use zip bags labeled warmth, traction, power and light, and food and first aid, so you can find things by feel with gloves on.

Cold-proof what goes inside

• Use lithium AA/AAA batteries, because alkalines lose most of their power below 0°F (-18°C).
• Pour about a quarter out of each sealed water bottle so it doesn't split when it freezes, and move one into the cabin on long trips.
• Choose food that stays chewable when frozen, like nuts, trail mix and soft granola bars. Hard protein bars turn into bricks.
• Charge the jump starter indoors to 100% and recheck it monthly, because cold drains lithium packs faster than you'd expect. Most packs should not be charged below freezing.
• If you use the triangles, set them out 100-300 ft (30-90 m) behind the car. In the UK, never place them on a motorway.

How to tell the kit is ready

Sit in the driver's seat with the lights off and gloves on. You should be able to find the flashlight and phone charger within 30 seconds, and assemble the shovel without taking your gloves off. Put a masking-tape label on the bin lid with the date you packed it. If the jump starter reads 100% and nothing in the bin rattles loose, you're done until the spring check. In spring, eat or replace the food and water, and take the jump starter indoors so summer heat doesn't damage it.