How to Keep Emergency Water in Your Vehicle Unfrozen During Winter

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If you live in cold country, you know that almost anything stored in your vehicle overnight is susceptible to freezing, especially water. You also know how handy a stash of bottled water can be in an emergency.

One of the most important items in any winter survival kit for your vehicle is water. It will stave off thirst and help you stay hydrated if you become stranded during a winter storm or blizzard. Unfortunately, water is also one of the things most quickly affected by sub-32 degrees temperatures.

So how do you protect your emergency water supply from turning into a block of ice encased in plastic with a screw top and keep it available for when you may need it most?

Keep Your Water Warm — Low Tech

There are three ways to help keep your emergency H2O  from freezing:

1.  Store your water in the passenger compartment of your vehicle with you, not in the trunk, because you will likely run your car’s heater during winter travels. This will help both you and your emergency water stay nice and warm, certainly much warmer than if you store your liquids in the trunk. I always store some extra water or drinks like Gatorade under the seats of my vehicle all year round, just in case.

2.  Keep your emergency water in a soft-sided insulated container, such as what Igloo, Coleman, and other manufacturers make for keeping your food and drink cool in summer. This will provide initial and ongoing protection from the cold regardless of where you store the H2O in your vehicle.

3.  Wrap your water containers in a Mylar survival blanket either in the trunk or main compartment of your vehicle if freezing temperatures are imminent. Don’t use your emergency wool blanket, sleeping bag or clothing, in case one of your water containers leaks!

Ideally, you should take at least 2 of these measures to help ensure your water doesn’t freeze.

If Hell Does Freeze Over…

In spite of your best efforts and precautions, if your emergency water is partially or fully frozen, do the following.

All of your water should be moved immediately from the trunk into the main part of the vehicle with you if it not regularly stored there already.

1.  Use chemical hand and/or foot warmers placed around your bottles of water. If you have or are using an insulated container, place the activated warmers right in with the bottles. I keep a modest supply of these chemical warmers in my winterized emergency kit for this and other uses.

2.  Instead of an insulated container, wrap a mylar emergency blanket around your water containers and activated chemical warmers -sort of like “pigs in a blanket”.

 3.  Lastly, place your water containers near the floor heating vent so that when you run your vehicle’s engine for 10 minutes every hour (read this article on How to Survive a Blizzard in Your Vehicle for more details), the heated air will help thaw your water.

When All Else Fails

As a last resort use a metal cup or can from your emergency kit (like a soup can or larger) along with a heat source like Sterno, to melt snow from outside your vehicle.

SURVIVAL TIP: You can use an emergency road flare as a heat source to melt snow into water. Just place snow in a metal cup or can. Ignite the flare. Hold the cup of snow above or to the side of the flare until snow melts. Be careful if you use this method. Safety flares burn at about 1,400 degrees Fahrenheit and emit phosphorus gases when burning.

One BIG Caution!

Do not be tempted to place frozen water bottles next to you in an attempt to melt the fluids inside. You will only cool yourself down faster which will promote the onset of hypothermia more quickly.

QUICK TIP: Use no larger than a pint to quart-size containers to store your emergency H2O in. Although the liquid stored in larger containers will take longer to freeze than the smaller size bottles, the smaller bottles are easier to store in small places in your vehicle and are quicker to thaw if they become frozen.

Water is a vital part of being prepared. How much do you need? How should you store it? To get the information with everything you need to know about water storage, containers, and what to have in your vehicles and check out these articles.

27 thoughts on “How to Keep Emergency Water in Your Vehicle Unfrozen During Winter”

  1. Some great tips on how to keep you water liquid in the cold! Thanks.

    Another thing you can do to prevent the water from freezing is adding a little bit of salt. Salty water freezes at a lower temperature. Add a little sugar to improve the taste and not only will your water be less likely to freeze but it will also help rehydrate your body faster. Salt and sugar are the main ingredients of both any over the counter Oral Rehydration Salts and sports drinks like Gatorade.

    Or you could of course buy some ORS and use that. But if you do make your own solution, be sure to try and taste different combinations of salt and sugar to find a combination that you and all your family members like (or at least don’t find disgusting ;).

  2. i carry those teeny packets of true lemon for flavor. gatorade has food coloring which we do not tolerate so make your own. i never thought of carrying sugar but i do carry salt. i’ll add some sugar to the supplies.

  3. my father told me in KOREA THAT the engines had to stay running in the winter time so the men would dream up small thin boxes 8 to 12 wide to hold water and place them in the engine compartment or a long the exhaust pipes also learn to warm up/ cook food on the engine block
    but you had keep seal from the gases coming out of the truck just get the heat

  4. If you have access to the mylar pouches, they won’t pop if the water freezes. Next best thing would be putting them in a bottle with ridges – more room for expansion if the water does freeze. It may be hard to deal with frozen water if you’re stuck somewhere, but it would be even worse to have it all over the floor of the trunk.
    Also, none of the first three would make much difference in my world with water left in the car for extended times.
    And while I have both water and “warmers” in the car I hadn’t thought of using them together. Thanks!

  5. This won’t work for areas that get really cold, but I’ve had good luck with Hawaiian Punch bottles. They’re squared, have ridges, and there’s a handle on the top. The plastic is much thicker than your average drink bottle. After cleaning them thoroughly, I fill them with water to about 2″ from the top. I’ve used them year-round for several years now, and I’ve never had one break, even when they were frozen and bouncing around.

  6. Here in Minnesota, where we have temps that can go to 40 below zero…that’s air temp.. and last for weeks…the only way is to melt snow. I have 2 winter emergency kits. The first one has all of the items that will not be affected by our extreme cold. When I know I am going to travel more than 5 miles, I bring a smaller bag containing food,water,medicines,batteries, chemical hand warmers etc. It sits by my front door with my keys attached. While it is a hassle to bring it back and forth to the house…my safety outweighs the hassle.

  7. Really your emergency kit, if you live in the kind of place that regularly freezes, needs to have a heat source of some kind. In Canada our emergency kits always have at least a few tea lights and waterproof matches or a lighter. There’s really no chance of a car that’s stored outside having water that *stays* unfrozen.

  8. My husband believes in “using” the engine warmth. He wraps burritoes in foil and warms them to lunch-temperature while driving around by placing on the air cleaner. It seems to me the same idea would work here. Keep a roll of foil handy – wrap some securely around a few frozen bottles of water, and place inside the engine compartment during that 10 minute an hour engine-on time slot. Yes, you’d have to be careful, but if it doesn’t burn my husband’s burrito, I would give it a chance not to melt the plastic bottle! Just wrap well in foil. He sets his lunch on the air cleaner – not “RIGHT” on the engine.

  9. Pingback: Winter Car Kit - Winterizing Your Car for Emergencies - The Hard Hat Belles

  10. Not the easiest but when you live where everything freezes regardless… simply taking water with you from the house every time. Not perfect, another thing to remember.. but it will mean you have water that isn’t frozen when you start.

  11. Pingback: Make Your Own Winter Survival Food Kit | O.G.C.

  12. Mylar blankets rely on the scientific principal of reflecting body heat to create warmth. I do not think that water bottles give off much body heat.

  13. Another Minnesotan here … I just use plastic soda bottles that are cleaned and refilled with water. Fill only 2/3 full, and squeeze bottle slightly when tightly screwing the top back on. This will help give plenty of room for freezing/expansion. This is not my first choice for drinking water (the plastic – ick!) but if you really are desperate to drink, it would be fine. It is also fine for grandkids who are carsick and need to rinse out their mouth and rinse their hands afterwards. 😉 I also have handfuls of the Handwarmer packets and will use them if necessary to heat up or unfreeze the water. Buy the heater packets at the end of season sales.

    1. I keep a plastic coffee can with a few plastic grocery bags to line the can and a few paper towels to absorb the liquid, some wet wipes, and a hand towel inside when I travel with my granddaughters who get car sick. I also keep a few peppermint candies in there to help with the bad aftertaste. We always carry water bottles in a smaller insulated bag as well as a few saltine crackers.

  14. I keep a small plastic jar of baking soda in my car. If someone gets carsick sprinkle the baking soda liberally on the area. The baking soda will absorb any liquid and help with the smell. Vacuum up when you get home.

  15. Very good article. Thank you. And some very good tips in the replies. Thank you all for those.

    I have one tip that I have used for years. While buying half-liter to full liter bottles of the (better) commercial waters is the easiest, and I do always have some in the truck, my primary supply is in partially filled MSR Hydromedary bags.

    I use stainless steel Kleen Kanteen 40-ounce single wall water bottles as part of my field kit that is kept in my truck. The trick I use to avoid the bottles being damaged if they freeze, is to not fill them full, and making sure that the pack is stored so the water bottles are laying at an angle.

    This way, not only is there room for the ice to expand, it is much less likely for the ice to damage the bottle as the force is spread out significantly more in the bottle since the surface of the water is much greater when the bottle is on a slant, than if standing straight up.

    Plus, the ice can form and push along the slanted side of the bottle much easier than if it forms in a static position and can only go straight up and to the sides, which can deform or even split the bottle.

    You can also do this with any bottle type water storage. Even new bottles of water can be opened, some poured out into an empty bottle, and the original bottle recapped and placed in storage on a slant.

    Of course, this does not prevent the water from freezing, but it does help prevent damage to the containers, and more importantly, the loss of the water once it begins to thaw and leak out of the damaged container.

    I also keep a Olicamp folding handle cup that will nest on the 40-ounce Kleen Kanteen, and a cup stove that nests over the cup, along with a lid, with the water. That way, if a container does split, I can put the ice in the cup and melt it so I do not lose it. It is also used to melt snow, if one of the other, quickly methods to melt larger quantities of snow cannot be done.

    From experience, I can tell you that it takes a very large amount of snow to get a useful amount of liquid water.

    Just my opinion.

  16. Good topic to discuss, thank you all. In my experience, melting snow has not worked. I tried it at home during a power outage: a huge saucepan of snow on a pot belly stove melted down to a tiny trickle of water in the bottom of the pan. There is very little water in snow; it is why you can’t rely on snow as a water source, but have to provide unfrozen water to farm animals.
    Does anyone know; is there a drinking fluid with a lower freezing point than water? Soups maybe? We keep warm blankets and coats, hand warmers, blankets, a charged phone and snack food in a container( chips, nuts etc) whenever we leave the house in winter. The only liquid though is a large thermos of coffee refilled whenever we leave; has anyone experienced heating bottles of water with hand warmers? Did it melt the plastic?

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