Hello Again and Welcome!

Hello everyone! Today, we are testing out the Extreme Cold Vapor Barrier Boots developed after the Korean War, aka the warmest boots on planet Earth. This is Michael, founder of the Iron Snail and CEO. Let’s get into this bunny boot review.

Today, we were talking about the Extreme Cold Vapor Barrier Boots by Bata, which you can sometimes get at army surplus stores. Right off the bat, these are obviously very serious boots. Each boot, in fact, weighs three and a quarter pounds, which is way more than you’d probably ever wear on your feet for any normal situation walking through the snow, unless you just live in like a very, very cold area.

These boots are absolutely not applicable and very, very heavy. They’re absolutely impenetrable to water. They don’t breathe at all, but wow, they’re very fascinating. There’s a lot of things to talk about today. Can’t wait for that!

So anyways, today we’re going to talk about the history of how we got to these boots because there’s actually a very fascinating two iterations of boots before this one.

And then we’ll talk about the boots itself, why the construction is so simple, the pluses, the minuses, why it’s so cool, and then I’ll leave, and you can go do whatever the heck you want.

The Original Mukluks

So the first boots that were widely circulated by the US Army – and then also did not go out of commission, a lot of other boots come up, but the originals also did not go out of commission, they just got updated – the first original ones were called mukluks. Mukluks are very interesting.

You’ve probably seen them a million times. They’re still used today, but the original ones were actually… I’ll just quote the ad: “Mukluks are the best footwear for the Arctic. They are made of tan leather bottoms with sturdy canvas duct tops. Inside are heavy woolen socks, a felt slipper, and a heavy burlap insole.”

That’s not what we typically see for boots today. We see mukluks a lot, or you see mukluks a lot if you’re anywhere that’s cold – they just don’t look like the old ones anymore.

But the reason that worked, and you had just canvas on top and leather on the bottom, is because those were for dry cold where it’s extremely cold outside, like negative temperatures, or just there is no slush – it is just freezing cold.

So you don’t really have to worry about water in general, and then those boots are extremely effective and they’re still extremely effective to this day. Their main benefit versus bunny boots is that they are breathable.

So obviously, mukluks, like I said, were good in dry cold, but when we got to wet cold, or soldiers had to go through water or anything like that, mukluks were no longer the best tool.

So that canvas upper, while it was so great that it was breathable, also the major downside, of course, was that it was breathable and water could permeate it.

Enter the Shoe Pack

There is, though, something in between a mukluk and a bunny boot, and that is literally basically just a combination of a mukluk and a bunny boot, aka a shoe pack. Shoe packs came about in World War II, it’s not a duck boot like what you see from L.L. Bean, but think like a Sorel Caribou boot.

They basically combine the best of both worlds, meaning that the upper part of the boot is breathable. It’s leather, and it’s a canvas – I think most things were canvas – and the bottom is typically a rubber, so it doesn’t breathe, but if you’re walking through slush, your feet stay drier than they did before.

Something important to note, though, is basically all of these boots are conditionally linked to the fact that you will have to take your boots off every once in a while to switch your socks, wring out your socks, or just drain the boots of sweat.

We have our three boots: we have mukluks, which are great for dry cold; we have snow packs, which are great for really kind of a mix and walking around in slushy cold; and then we have Extreme Cold Vapor Barrier Boots. And after that, the Korean War happened, and that… that was cold.

That was very, very cold. So cold to the fact that mukluks and shoe packs were not cutting it anymore. Soldiers were getting frostbite, and it was very bad.

Boot Comparison Overview

The Evolution of Cold Weather Boots

I don’t know the perspective of the designers who made the bunny boot and the Mickey Mouse boot, but the perspective was that “we just need to protect these people’s feet.”

They don’t need to be super light, and they don’t need to be incredibly comfortable. They don’t need to be breathable – we just don’t want to have frostbite and feet that we have to chop off anymore.

So first things first, they made the Mickey Mouse boot, which was black and good to negative 20 degrees Fahrenheit. That still wasn’t good enough, so they quickly iterated to what I’m talking about today – the bunny boot, which is good to negative 60 degrees Fahrenheit, and that did the trick.

But even then, apparently, it was so cold that there were a lot of disclaimers with these boots, or just the army itself said these are good to negative 60 degrees, make sure you keep moving. These boots – their only goal is to be warm, and that is it.

Boot Construction

But the basic construction of all three of these boots is essentially the same except for the outside. The bottom has a ton of felted wool – there is an inch and a half, two inches of felted wool.

Then, on the top, around the boot on the actual foot part – pay attention to that – there is less wool but still a lot, probably a half inch, which is still a ton of wool.

Then you, of course, are expected to wear one or two pairs of wool socks that you’ll be switching out through the day because your feet will be so sweaty, and that’s that.

The Science Behind the Valve

What makes these boots so special is what the valve is on the side, and you may be thinking, “What is the valve on the side?” Well, all of these insulators – wool, down, synthetic, anything like that – their main goal is to trap air and keep it close to your body.

You warm up that air with your body heat, and then since it’s held there, it returns a favor back to you, and then you keep warming it as that air blows away, or whatever it may be.

So there’s wool, and then obviously the outside is rubber, so no air gets in and out. So your feet warm up the wool, and it basically stays like that.

That’s why it’s okay if your feet are very sweaty because these boots could literally fill up with water and still be warm because the air does not come in and out – the rubber takes care of that, and wool is still very very insulating when wet.

The other fascinating part – and I’m not positive about this, so this part may not be 100% correct – but the foot, the actual foot part of the boot, is wool, there’s only wool insulation, and then coming up the ankle, we have basically two layers of rubber with air in between. And if you under this valve, that little layer opens up and the air comes out.

The only purpose of that valve is when you’re going on a plane with these boots. If you don’t do that, there’s a possibility that that little pocket of air will rupture with a pressure change, so you’re supposed to do that so the air comes in and out. You should really, other than that, never unscrew those.

But when you need more mobility, an inch, a half inch, or two inches of wool is not good for that, and you need mobility to bend your feet and move your feet side to side, so that’s where I think this little air pocket comes in.

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Final Thoughts

Anyway, I have a final thought for this bunny boot review, and it ties in with my new Yeti. I have a Yeti Rambler that my mom and dad got me for Christmas. That’s amazing, but I poured the tea in for it at like 10 AM, and I wanted to drink it at 10:15. When I got back to it around 4:30 PM, it was still pretty hot. So as an effective tool for me to drink my tea within 15 minutes of pouring it – very ineffective and overkill.

Where I am, it’s like 30 degrees, and wearing the warmest boots on earth is essentially me trying to drink scalding hot water out of my Yeti at 10:15. And if you’re a soldier, you’re probably thinking, “Thank God that little guy with the boots on that looks like an elf is not the person that was serving this country.”

Almost Forgot! Quick Sizing Tip

If you’re looking for the size, I went true to size – normally an eight, and stuck it with an eight, it fits fine, and it accounts for like two layers of wool socks, so you can’t beat them. They’re great boots. Bunny boot review is done! Time for me to go, bye!

This article was adapted from Michael Kristy’s video on The Iron Snail, with edits from FashionBeans, and was reviewed by Michael to ensure the integrity of his original content. Watch the full video here.