Let's talk coldweather prep.
Since Pennsylvania is being all northern this past week and getting down to single digits with wind-chill well below zero, I'm taking a look at my own preparation for winter weather, and refining what I keep on hand.
So here's my current recommendations. (Including a few that I don’t have yet, but want to add to my own prep). Throw your additions, suggestions, or cautions in the comments!
Vehicle:
A good battery and a full tank, with a spare can of gas. Ice scraper, shovel, some ashes or salt. A heavy jacket, spare gloves, and a wool blanket or two in the back seat. A tarp and a camp stove wouldn't be foolish. High calorie nonperishable food. Bottled water. (Yes, it will freeze. But in an emergency, it’s good clean ice and can be thawed for clean drinking water.)
Home:
Block all drafts, including plastic on leaky windows. Insulate water pipes, install heat tape, or let vulnerable faucets drip during cold snaps (if it’s really cold, let them trickle; a drip won’t do it). An adequate heating system and a backup. (I run dual electric and LP heat, with a wood stove available for backup in a worst case scenario.) If practical with your heating system, consider closing off unused rooms. Warm blankets. Nourishing food, and a teakettle on the stove for hot drinks and a bit of moisture in the air.
Clothes:
Base layers. Wool if possible ($$$), or synthetic. Cotton stays wet, and loses insulating properties quickly. Extra sweaters, sweatpants, warm socks, slippers, and beanies. Boots with Thinsulate (I'm wearing Ranger brand, which are too heavy for comfortable everyday wear but will keep me warm outdoors in subzero temps). Gloves (my favorite is the cheap cotton gloves from the dollar store with waterproof nitrile overtop, with Thinsulate mitts over that. It's the best combo of warmth and dexterity I know of). A heavy, windproof jacket/parka.
When it comes to clothing, layers are king. Heat loss is a function of how many air gaps (air trapped between layers) you have, not necessarily how thick your clothes are. This is why fluffy down jackets or “puffers” are so cozy. We lose heat through radiation (heat passively moving from your warm body into the colder air surrounding), through convection (air actively moving heat away), conduction (heat transferring directly from one object to another through contact, like your body on cold ground. Technically this also applies to contact with air that is colder than your body), and through evaporation (heat loss through water evaporating, whether from sweat or from otherwise getting wet). Staying warm in an emergency requires addressing all of these. So make sure you are insulated from the cold ground, that you have a windbreak, that your clothes are dry, and that you have sufficient layers and/or heat.
So. Go for multiple layers, with a wicking layer next to the skin, and a wind-resistant outer layer.
(For more information on heat loss/staying warm, hit up the latest blog post on Tuff Possum Gear. Jayberry geeks out on this stuff, and this post is gold for any cold weather enthusiast.)
Food:
Staying warm burns extra calories. Especially if you need to be outside or in an unheated building for any length of time. Expect to double or even triple your typical caloric needs if you’re out in the cold. 7,000 calories per day is a reasonable expectation for cold weather hiking, snowshoeing, search-and-rescue work, etc.
Soups, stews, and other hot food is a psychological necessity, and a good way to get nourishing calories aboard. Hot liquids are nice, too. But, dehydration is a common cause of cold related medical emergencies, and cold liquids are fine. Keep a stash of nonperishables that don't need heating, like jerky and candybars.
Worst case: Be thinking of the major categories that you’ll need: Shelter, heat, food, water. Plan for where YOU live. If you live in a cold area, knowing how to find shelter and heat will be crucial, whereas if you’re in a hot area, water will move up on the priority list.