1. Get helpRoadside assistance: Many new cars include a roadside assistance program which will provide towing if your car breaks down. The American Automobile Association (AAA) and Canadian Automobile Association (CAA) are probably the best-known and most reliable third-party roadside assistance programs.
Mobile phone and car charger: If you don't have a mobile phone, buy an inexpensive pre-paid unit to keep in your car so you can call for assistance. Make sure you have a car charger; some phones can also be charged from your car's USB port.
OnStar: An option on many new cars, the OnStar system can get a live operator on the phone with the press of a button, and will automatically summon help if your car's airbags deploy. OnStar relies on the vehicle electrical system, so carry a cell phone as a backup.
2. Stay safeEmergency flares and/or hazard triangles: Winter accidents frequently result in damage to your car's taillights, which means your hazard flashers will not work. In a snowstorm, other cars may not see your car until it's too late to avoid it. Set out flares or hazard triangles to warn cars and avoid a second collision. In the event the car goes off the road in deep snow, these items can also help emergency services personnel locate you and your car.
First aid kit (compare prices): Bad weather may delay emergency workers, so it's a good idea to carry a simple first aid kit.
Small LED flashlight: Don't rely on the vehicle's electrical system for light -- if it's working, you want to conserve the car's battery as long as possible. LED flashlights use much less energy than regular incandescent flashlights, making them a great choice for your emergency kit. The Mini Maglite LED is more expensive than many small flashlights (around $18, compare prices), but its rugged construction makes it worth the price.
3. Stay warmEmergency blanket: Cars use the engine to produce heat, so if the engine conks out, so does the heater. Even if the engine is working - say, after an accident - running it is a safety gamble, because if the exhaust system has rust holes or damage, fatal exhaust fumes can seep into the passenger compartment. Besides, your car may not be the safest place to be in an emergency. Emergency blankets are small, light and cheap (less than $5, compare prices). Buy extras if you frequently travel with passengers.
Ski hats: Experts say that 30 to 40 percent of body heat can be lost through the head. Carry a few inexpensive beanie-style winter hats, big enough to cover the ears.
4. Stay occupiedChildren's books or games: If you travel with children, keep a few emergency activities stowed away to fight boredom and keep the kids occupied while you wait for help.
Read more: Travel games to play with kidsNon-perishable snacks: Munchies help pass the time and will keep your energy and morale up while you wait for help. You don't need to lay in supplies for a week-long stay; a couple of granola bars and/or some dried fruit or nuts in a non-glass container will suffice.
Where to carry your emergency kitThe most logical place to store your emergency kit would be the trunk -- problem is if you're in a collision that damages the rear end of the car, you may not be able to get the trunk open. Instead, carry your emergency kit in a small duffel bag stored in the passenger's footwell, where it can be easily accessed by the driver (and where it won't become a projectile in a collision). If your kit includes flares and you travel with children, store the flares in the trunk and keep a backup hazard triangle in the bag.