How to Store Emergency Water in Your Car

How to Store Emergency Water in Your Car so It Lasts

It’s a pretty well known fact that humans need water to survive. For those who prefer to be prepared at all times, in the event of disaster or mild discomfort, it can be a good idea to store water in your car. Storing water in your car is a smart option instead of having to buy water when you’re traveling.

Water may not be available while traveling, especially in a disaster situation. Or water might be way too expensive at certain destinations, like at a certain mouse-centric theme park, for example. Car stored water is also ideal for camping and hiking, which usually take place in locations that don’t exactly have mini-marts full of water.

However, as smart as the idea is to keep extra water stored in your car for these situations, there are a few problems associated with the practice if you do not take the proper precautions.

Storing Emergency Water in a Hot Car

If you live in a very hot or desert region, the inside of your car can easily heat up to triple digits, even hotter than the exterior of the car. This is because car windows act like magnifying glasses for the sunlight coming through. If all the windows in the car are rolled up, then there is no ventilation for the stale, simmering heat. Basically you are driving a giant solar oven.

So if you are keeping store bought plastic water bottles in your hot car, chances are the water is slowly being poisoned. Sunlight and heat will weaken the plastic of most water bottles and leach the BPA’s from them and allow it to contaminate the water. BPA’s are bad news for your body. They are chemicals that have been known to cause cancer, high blood pressure and brain problems, particularly in children and unborn fetuses.

Also if the water heats up in the car, it tastes unpleasantly hot and like plastic, which of course can be a huge turn-off on a blistering day.

A soldier loading water into a truck.
Using your car to transport bottle water is fine. Using your car as a long term place to store your bottled water is not, unless you take extra precautions.

Solutions for Hot Climates

Luckily there are many simple solutions for making sure that the water you store in your car will stay fresh for long periods of time, even in very hot climates. Using one of these solutions can keep those harmful BPA’s out of your water and ensure it wont taste like plastic after a few weeks in your car.

1. Non-Plastic Containers

One option is to buy glass bottles and fill them with water at home before storing them in your car. While the water may still be warm to taste, at least there won’t be poisonous BPA’s floating around, seeping into your body as you drink. The water should also taste good even after extended periods of time in a warm car.

There are other kinds of bottles that you can use as well, including stainless steel and specialized plastic that doesn’t secrete dangerous chemicals. There are multiple models and kinds available on the market. However, if you still don’t like the taste of hot water from a glass or steel bottle, there are a couple extra precautions you can take to beat the heat.

2. Store the Water in the Trunk

One great tip is to store glass bottles or stainless steel bottles of water in the trunk instead of the cab of the car. It may still be hot but the sun isn’t directly piercing it, which will help immensely. The temperatures in the trunk area don’t swing quite a drastically as they do in the cab.

3. Use a Cooler

Another clever solution is to store a cooler or ice chest in the trunk with the water bottles inside, as suggested in this thread on the EDC forums. The water will still get warm but this extra step insulates the bottles from the worst of the heat on the hottest days and stops any potential sunlight from getting through the plastic or glass.

4. Buy Canned Emergency Water

Consider buying a case of emergency water that is in canned form, such as these Blue Can brand emergency cans of water. These boast a 50 year shelf life, although I would suspect they will likely last indefinitely. The great thing about water being contained in an aluminum can is that they will not leach chemicals into your water, no matter how hot your car gets! You’ll always have good tasting water ready when you need it.

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How to Keep Your Water from Freezing in a Cold Car

Not everyone lives in the desert of course. Some people live in Alaska, Canada, and other very cold places, but still need to keep emergency water stored in their vehicle. Those that are stuck in freezing temperatures face unique challenges including keeping their water unfrozen and warm enough to drink. Being stuck in a blizzard with nothing to drink but a bottle of ice is truly a disaster scenario.

Another major issue is if the water is stored in a rigid container such as a stainless steel water bottle when it freezes, the bottle will likely deform or even explode. This will destroy your bottle and leak the water out all over the inside of your vehicle potentially damaging your vehicle’s interior and leaving you with no emergency water when you need it most.

Most people underestimate how much water they need when it’s cold outside. Even though it’s cold and wet out, your body still needs water to keep functioning. This tends to happen a lot when people do snow sports or go hiking in the snow.

Water bottles left in a cold car can freeze.
Frozen bottles of emergency water in a car are not much good in a disaster situation.

Solutions for Cold Climates

Luckily there are a few solutions to these problems that can be used to ensure that your water will remain ready to drink, and inside it’s container.

1. Warm It Up In the Car

Unlike the desert scenario, you will want to keep bottled water in the cab of the car instead of the trunk. The sun’s rays and BPA’s are not the major concern here because of the cool climate. You’ll be likely often be running the heater in your car and it will help warm up the water if it is in the cab with you, keeping it liquid. Putting it on the floor nearest to a heating vent will accelerate this process.

2. Use a Cooler

Believe it or not, an ice chest or cooler will still provide insulation against harsh temperatures in this situation. It will actually keep the water warmer instead of cooler. You can take an extra step and wrap your waters in blankets for additional insulation. The water will still get cold but by being insulated, it will keep them slightly warmer on the coldest of days which may allow them to stay liquid.

3. Use Plastic Bottles

Plastic bottles are the worst container for those in hot climates, but they may be the best solution for those in cold climates. This is because glass and stainless steel containers will burst if the liquid inside them is frozen. This is due to their rigidity which doesn’t go well with the expanding effect of water that begins to freeze. Plastic on the other hand, can flex and expand ever so slightly (usually) without bursting.

Imagine your disappointment when you want to stay hydrated and alive, only to have your emergency water source blow up in your hands and soak into your clothes. Then you’ll be dying of thirst and hypothermia! Definitely stick to plastic if you plan to store your water in colder climates.

BPA’s from the plastic water bottles leaching into your water is not a major concern in colder climates either since the plastic’s integrity is really only compromised by heat. Without heat, very little BPA’s will ever make it into your drinking water.

Frozen versus unfrozen bottles of water.
A frozen plastic bottle of water (bottom) will expand slightly as compared to a non-frozen bottle (top). This slight amount of give in the plastic will keep the bottle from bursting.

4. Have a Means to Thaw the Frozen Water

If your water does freeze, never attempt to thaw it out by cuddling with it and using your own body heat. The water bottle won’t be affected much, but your body temperature will drop like a rock and increase the chances for hypothermia to set in if you are in a survival situation.

Have a means other than your body heat to thaw your water should it be frozen when you need it. Consider placing hand warmers against the bottles of water and wrapping them in Mylar emergency blankets. Mylar emergency blankets and hand warmers will both last indefinitely in your car and can be easily tucked away in a spare compartment for this purpose.


Storing water in your car is a very smart way to be prepared for a survival situation or just to stay hydrated. Although it’s not as simple as chucking a palette of store-bought bottled water in the trunk and calling it a day. There’s some preparation involved for the best possible quality and taste of your water.

While this preparation may require some time and investment, it’s well worth it. Staying hydrated every day is too important to skimp on, especially if you get stuck somewhere in a situation where water is not available. Just be sure to be smart about what containers to choose and where to store them.

John Walter

John Walter is an emergency preparedness consultant with eight years of experience and training in related fields. He is a passionate prepper living in the Sacramento area of California.

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