Are Mr. Heaters safe in a tent? (Fact checked)

Are Mr. Heaters safe to use in a tent? Many use Mr. Heater Buddys (and other models) as their primary outdoor heat source.

They are great in cabins, RVs, and in workshops. But can you use a Mr. Heater in your tent?

In this article, we will check whether Mr. Heaters can ignite or melt tent walls and whether they emit carbon monoxide. And of course, we will check whether it’s possible to run a Mr. Heater for a full night in a tent.

Quick answer: Mr. Heater Buddy and Big Buddy heaters are only safe to use in >3-person tents. For smaller tents, you should get the Little Buddy heater. Mr. Heater propane heaters are safe to use in a tent of adequate size. Never use them in a crowded tent. They can theoretically ignite or melt the tent walls. So, make sure to be careful. Mr. Heater propane heaters will not emit carbon monoxide inside a tent.

In this article, I measured the temperatures my Mr. Heater Buddy outputs and how they compare to tent wall melting and ignition temperatures!

To save you some time, here’s the quick result.

Which heater is good for which tent size?

Which Mr. Heater you can use for your tent mainly depends on the tent size. Here’s a quick summary:

Can a Mr. Heater ignite a tent?

Whether a Mr. Heater can ignite or melt a tent wall depends on two things: The temperature of the air leaving a Mr. Heater propane heater, and, of course, the ignition or melting temperature of tent walls.

Let’s have a look at these things:

How do Mr. Heaters distribute the heat?

Mr. Heaters have a very special heat distribution. They look like infrared heaters because of the glowing ceramic tile, which acts as the heating element.

Infrared heaters radiate the heat in one direction. So, an infrared heater will heat only the things in front of them.

However, Mr. Heater Buddy heaters only look like infrared heaters, but they are mainly convection heaters.

Convection heaters are heaters that emit heat as hot air, rather than radiation.

The hot air coming from a convection heater always rises straight to the top (except if there is a built-in fan in the heater). Most Mr. Heaters don’t have built-in fans. Which I like a lot, as this reduces noise and maintenance.

Most of the heat from a Mr. Heater Buddy heater rises upward through the top vents.

The burning ceramic tile only creates the illusion of an infrared heater.

I’d estimate that Mr. Heater Buddy heaters emit 70% of their heat as convection and 30% as radiation.

This means that most of the heat rises straight up to the tent walls or roof.

If you place your Mr. Heater in a tight corner, the tent walls can heat up quickly.

Which temperatures do tent walls withstand?

A lot of engineering goes into making tent walls. They have to be lightweight, water and windproof.

I assume that the light weight makes tent walls especially prone to fire. You could argue that tent walls are very dense (to repel water and wind). However, tent walls are very thin. So, they heat up quickly!

Tent walls are made of the following materials.

These are the ignition temperatures of different materials when you ignite them through kindling.

The autoignition temperature is the temperature at which different materials catch flame on their own.

The autoignition temperature of cotton is 764°F (407°C). Canvas is made of cotton, so its autoignition temperature is the same.

Polyester starts melting at 810°F (432°C). And Nylon melts at 516°F (269°C).

Since you usually don’t ignite your tent on purpose, the autoignition and melting temperatures are important.

And as you can see, most tent materials start failing in some way around 400°F. Except for Polyester, which withstands higher temperatures.

How hot do Mr. Heater Buddy heaters get?

Now to find out whether Mr. Heater Buddy heaters can ignite a tent, let’s have a look at the temperatures they emit.

The ceramic heating tile of a Mr. Heater Buddy gets well over 1,100°F. I used a laser thermometer to measure the temperature of my Mr. Heater, and this is the temperature reading I got.

The measurement is, however, off, since this is the end of the measuring range of my thermometer. So, the heating tile is likely significantly hotter.

A blue propane flame burns at 3,596°F (1,980°C). So, that’s the maximum temperature you are theoretically able to measure in a Mr. Heater Buddy.

However, since the ceramic tile absorbs the propane flame heat and distributes it via convection and radiation, the heat leaving the Mr. Heater is lower than that.

In very close proximity to the Mr. Heater (e.g. right in front of the ceramic heating tile and the air vents on top), you can measure temperatures of >800°F.

This is enough to ignite or melt tent walls that are close to the Mr. Heater. 

The table below lists whether you can safely use your Mr. Heater in a tent or not:

1 and 2 person tents usually don’t have enough space to run a Mr. Heater.

3 person tents barely have enough space to run a Mr. Heater. So, you can theoretically use a Mr. Heater in a 3-person tent. But you should be extra careful because the space is getting very tight.

You can safely use a Mr. Heater in a 3-person tent if only 2 people are present in that tent.

Can you run a Mr. Heater overnight in a tent?

Yes, you can run a Mr. Heater overnight in a tent. However, make sure that your tent is large enough for your Mr. Heater to have enough space.

Mr. Heaters get very hot and, therefore, you need to have a tent with enough space for the heat to distribute before it reaches the walls and tent roof.

And additionally, run your heater on the lowest setting to get the longest heating duration.

Unfortunately, Mr. Heater Buddy heaters only last 5.4h on the lowest setting on a 1-pound bottle.

So, Mr. Heater Buddy heaters don’t last for a full night of sleep.

To heat for a full night, you either need two 1-pound propane bottles. Or you need to bring a larger tank.

Do Mr. Heaters emit carbon monoxide in a tent?

Mr. Heater Buddy heaters do not emit carbon monoxide in a tent. They can only theoretically emit carbon monoxide in perfectly insulated rooms that lack oxygen.

However, a tent always has air gaps. And tent walls oftentimes also allow air to pass.

Mr. Heaters can only emit carbon monoxide in fully-sealed plastic wall tents, where no oxygen can enter.

You should never sleep in such a tent anyways.

In every regular tent, you don’t need to worry about carbon monoxide production.

Philosophy: Should you use a propane heater in a tent?

Running a Mr. Heater propane heater in a tent is not safe. If it was safe, you would know and you would not have to read this article.

I approach problems like this the following way:

What are the risks and benefits of running a Mr. Heater in a tent?

The best possible outcome is that you spend a cozy night in your tent. The worst possible outcome is that you die in a tent fire. The mega-worst case is that you die and you cause a wildfire at the same time.

So, the risk-benefit ratio is a bit off. You risk lives for your own luxury.

Because of that, I generally recommend preferring warm clothes and a good sleeping bag over heaters.

A good sleeping bag is a one-off expense. You buy it once and it lasts you for many years, likely even decades.

Another thought:

Does your life depend on the tent?

You are looking for a heater to use in your tent because you are about to spend a (very) cold night.

Cold nights can be life-threatening.

With a heater, you risk burning your tent. So, especially when you need your tent for multiple nights, you should not bring a heater with you.

Imagine you’re going camping in cold Alaska. After a long flight, you spend your first night somewhere in the wild. You turn on your heater and it melts a hole into the tent wall.

Nice…

Now, you are left with a tent that lets cold air in for the rest of your trip. And there’s no going back.

If you really depend on the tent, don’t risk it.

If you are spending a chilly spring or summer night in your tent not too far from home (or at least in your own country), then go for it and use a Mr. Heater Buddy in your tent.

Since you don’t really depend on your tent, you can risk losing it.

Recommended heater for tents

Now, before you leave for your camping trip, get the right Mr. Heater model!

Mr. Heater Buddy heaters are too big for 2-3 person tents. And they use up a lot of propane.

Instead, use the Mr. Heater Little Buddy (click here to view it on amazon) for tent heating!

It is strong enough to keep your tent warm at night, and small enough to be used in small tents.

Additionally, the heating head is angled at a 45° angle. So, the heat does not rise up the tent walls and melts through them, but it moves along the inner shape of the tent!

This reduces the risk of burning holes where you don’t want them.

The running time of a Mr. Heater Little Buddy is 5.6h on a 1lb propane bottle. So, they last slightly longer than the bigger Buddy and Big Buddy models.