With winter coming, I thought it would be good to talk about how I keep warm in my van.  The first part of this post is about passive warmth.  The second part is about active warmth.

Within the scope of this article, “passive” means preserving your body heat and “active” refers to using heaters.  Where appropriate, I’ve put Amazon links, but you can buy much of this gear at Walmart and Home Depot.

My Bed

When we talk about keeping warm in the outdoors, we often use the term “base layer.”  A base layer in clothing terms is your Under Armor or thermal underwear.  My “base layer” is my Coleman Cot.

This cot has a removable (for warm weather) foam mattress, which is a good starting point for insulation.

I’ve talked about this awesome cot in the past, so I won’t spend much time on it here other than to say it is sturdy, comfortable, and quiet.  If you want one, you can get it delivered for about $80.


If you have a platform bed in your minivan RV or van camper, you won’t need the cot; your base layer is the mattress or foam pad.  Adding a layer of closed-cell packing foam or Reflectix can improve its insulating properties.

When it gets cold out, I add a layer of Reflectix under my mattress, on top of the cot’s webbing.  Reflectix is a rugged, bubble-wrap type product that provides some limited insulation and radiant heat (body heat) reflection.  But it has two other important qualities.  First, it provides a vapor barrier between you and your platform (this is less important on a cot).  That cuts down on the stank transfer to your plywood, from perspiration.  It also provides a nice layer of cushioning.  When you kneel on the bed or otherwise move in a way that would bottom out the cushions, you have an extra layer of cushioning before you hit the wood.  You can easily roll it up when not in use.  Mine serves double duty as a windshield sunscreen in the hot and insulation in the cold.

You can buy Reflectix on Amazon, but it’s generally priced lower at your local Lowes or Home Depot, so I won’t bother with an Amazon link.  Find it near the 4×8 foot sheets of foam insulation.

Now that we’ve got a good base layer going, your next stop is your blankets or sleeping bag.  I prefer bags in cold weather because they don’t slide off and they keep out drafts, but I travel alone.  If you travel with someone else, a good argument can be made for sharing warmth under the same blanket.  Other arguments can be made for sharing warmth, but this is a family-friendly site.

(I endorse Passport America.  It’s a good program for frequent travelers!)

With either arrangement, it’s good to have a couple of layers.  I travel with 3 season bag and a summer weight sleeping bag (the flannel one in the photo).  That gives me a couple of choices, depending on what kind of weather is coming.  When it turns cold, I sleep in the 3-season with the zipper facing the non-zipper edge of the other bag.  Note that in the picture, I’ve put one side of the outer bag UNDER me.  Although you will lose most of your heat out the top, as anyone who’s slept on the ground will tell you, whatever you are sleeping on will also conduct body heat away.

This arrangement has let me sleep through the night, down to 22 (F), so far.  Note that you can pretty much ignore sleeping bag temperature ratings, other than for relative comparison.  When a bag says it’s “good to 20F”, or “rated to 20 degrees”, that pretty much means you won’t die at 20 degrees, but you’re not going to be toasty warm either.

Sleeping bags are a subjective purchase, but if you want my suggestion, here are the two that I use.

Once you get a fabric cot, a layer of Reflectix, and a nylon sleeping bag together, you may find that they slip around when you toss and turn.  If that bothers you, a couple of feet of this stuff placed between each layer will keep everything in place.

It also keeps your bed from sliding off onto the floor, while you are driving around.

The last part of my “passive” strategy is a helmet liner (aka Skully)  hat to keep my head warm.  You don’t need to do this, but you will lose a lot of heat out of your head if you don’t.  I don’t like to sleep with a bulky hat because you always seem to have a lump under your ear or something.  The helmet liner is smooth and when it’s not cold, you can store it in your jacket pocket.  They are also great outside and keep your ears warm on the windy days in the 30s.  I like this one and keep a few around.

It’s Electric!

As it gets colder, you can add layers on top, but all those blankets get bulky and waste valuable room, so I’ve been experimenting with this.

Sunbeam, the electric blanket people, make a nice electrically heated fleece throw that I’ve now used down to 22 F…on the medium setting.  Used as described below, I think it would keep you warm down into the teens.  I will try that when it gets cold enough, but for now, I’ve tested down to 22 degrees in the Organ Mountains at Aguirre Springs.  At 50 in x 60 in, it covers the majority of my body and overhangs the sides of the cot when I’m under it.

I’ve thrown it on top of the cot in the photo, so you can see the size.  However, the best way to use it is to add it between the inner and outer sleeping bag or blanket.  By itself, the fleece provides warmth, but once you plug it in…oh man!  It has not been cold enough to test it under 22 degrees F, but I’ll bet it will be good enough for most winters in the lower 48 states.

A nice side benefit of the blanket is that you can pre-heat your bed.  That may not sound like a big deal, but when your bed is 30 degrees, it cuts down on the swearing at bedtime.

This type of electric blanket also uses very little power.  It doesn’t seem to matter if it is on low, med, or high, with the power consumption staying between 50-60 Watts (W).  To test this I plugged in my handy Kill-A-Watt (reviewed in this post).

Here are the Power (Watts) and Current (Amps) draws at each setting.

This means you could run this on a 100W inverter!*

There was no correlation between the power draw I measured and the setting of the controller.  On all settings, it fluctuated between 50 and 60 Watts.  This makes me think that the controller isn’t actually varying the current going to the heating element, but the time it is on/off.  So the maximum this electric fleece should use is 60 Watts. (Electric Fleece, Odyssey, Golden Fleece, Odysseus—I’m sure there is a good joke in here somewhere!)

*So now that I have you convinced that you need one of these electric fleeces, there is a small problem.  Attached to the control unit was this warning that you should NOT use it with an inverter!!!

I did a little digging into this and apparently, the restriction is on “modified sine wave” inverters.  Modified sine wave inverters (MSW inverters) do not provide a perfectly smooth sinusoidal wave, which causes issues with the electric blanket controller.

A full explanation of the inverter/electric blanket issue can be found here.

Unfortunately, most of the inverters you will find for under $100 are modified sine wave inverters.  (Update: I found this one for $48 on Amazon):

If you want to run an electric blanket, make sure you have a “true sine wave”  or “pure sine wave” inverter.  If it does not say this in the name or specs, it is probably a “modified sine wave” inverter.  That means it will work with 99% of the appliances out there, but not your blanket.

Fortunately, the price of true sine wave inverters has come WAY down in recent years, approaching that of the cheap MSW ones.  I have upgraded to this Full Sine Wave Inverter that supports 1500W output and a surge of 3000 Watts!   That means if you have thick enough cables feeding it from your battery, you can run anything that you would plug into a home 120v outlet.  A hairdryer, a microwave, or a coffee maker.  This is a big bad inverter that will cover most of your needs now and going forward.  It’s not the cheapest, but it will seem like cheap money when you need it.

Novapal Inverter on Amazon $139-$219

If the $218 price tag is a little steep for you, they make a 1000W version of the same product for $139.  Just look for the variants under where the price is listed.  1000W with a 2000W surge is still a lot of inverter and will cover everything short of a hairdryer or microwave oven.  It even has a remote on/off switch, so you can hide it out of the way.

If you do not have the right inverter yet, you can still use this electric fleece, but you’ll have to plug it into external power (i.e. a wall plug or outlet at your campsite.  The Sunbeam Electric Fleece is available from Amazon.

I think that the best strategy for keeping warm at night is this small electric blanket, along with the passive strategies above.  It’s a more efficient way to keep warm while you sleep, than heating the whole van or RV.  While you are awake, a small electric heater can keep things bearable down to 40 degrees or so.  I use the following one, which I could easily run off of my old 800W inverter.  It has two settings (170W and 250W) and works great in my small Honda Odyssey “mini” van RV.  If you’ve got a full-size van, keep reading.

When it gets under 40 degrees and you want to heat the space in your minivan, or if you have something larger than my Odyssey, you’ll need to move up to something like the Mr. Heater, Buddy.

Mr. Heater, portable propane heater $85

I’ll say upfront that I’ve never needed to use one of these, but if you are in a big vehicle and/or very cold weather, they can be lifesavers.  They put out a LOT of heat using a small propane bottle.  You can also bring them outside on cold nights as they are radiant heaters that heat you as well as the air.  However, there is something that I DON’T like about these heaters.  I have used propane heaters in enclosed spaces before and they tend to generate a lot of moisture.  For this reason, it might be a good idea to run this when you are awake, but use the above strategies for sleeping.  Make sure to leave a window cracked to let fresh air in and moisture out.  The issue with these heaters isn’t the CO (carbon monoxide) but rather the use of oxygen.  They will automatically shut off if the oxygen level gets low, but I’d err on the side of caution and leave a window cracked.

I hope that all of this information and testing helps to keep you warm this winter.  These aren’t the ONLY strategies to stay warm, just the ones I’ve used.  Borrow what works for you and change what doesn’t.  If you liked what you read here, please like us on Facebook @OdysseyCamper, or subscribe to our YouTube Channel

Thanks for reading!

–Odyssey Camper

Want to find great, out of the way campsites? When I’m not boondocking for free, I use my Passport America membership to save 50% on campgrounds.  It pays itself back after a couple nights and then cuts campground costs in HALF!

Don’t get stuck buying a separate membership for each campground chain, join Passport America instead!

–Odyssey Camper