How To Hide From Thermal Vision

Fergus Mason
By Fergus Mason January 16, 2017 14:42

How To Hide From Thermal Vision

Modern surveillance technology can be scarily effective, and it’s getting better all the time.

The first night vision device I ever used was an old Individual Weapon Sight, a huge starlight scope that cost as much as a pretty good car and weighed more than the L1A1 battle rifle it was mounted on.

Now a few hundred dollars will buy you a much more effective night sight that weighs a few ounces, or a good set of night vision goggles – but night vision is old technology now. The state of the art in surveillance is thermal imaging, and that’s a lot harder to hide from.

Night Vision Vs Thermal Vision

Thermal imaging is also called passive infrared. It works by picking up the infrared radiation – basically heat – radiated by objects, and displaying the different temperatures. It doesn’t matter how expertly camouflaged something is – if it’s warmer or cooler than its background, it will show up.

The effective range of a thermal imager is from a few dozen yards for the smallest handheld units, up to thousands of yards for large military surveillance systems and weapon sights. And, while imagers were once heavy and incredibly expensive systems that needed to be cooled with refrigerated gas, they’ve become a lot smaller and more affordable.

Less than $2,000 will buy you a rifle scope that lets you shoot out to more than 300 yards in complete darkness. For $600 you can get a hand-held imager with a range of over 100 yards. You can even get a $249 plug-in module for your smartphone that will pick up a hidden object a few yards away by its thermal emissions. These days, if someone’s looking for you it’s smart to assume they have a thermal imager to help them.

Does this sound like bad news? It is.

Unlike standard night vision devices, thermal imagers don’t need any light at all to pick you up. They can see through mist and smoke. They penetrate rain and falling snow, although those can reduce their range by more than half. If a thermal imager is scanning for you it’s a lot harder to hide. But it isn’t impossible, and if you know what you’re doing you have a good chance of evading detection. Here’s how to do it.

Remember the basics

Hiding from a thermal imager follows the same basic principles as hiding from anything else. Your challenge is to avoid standing out in the sensor display. If your pursuer has a conventional scope you do that with camouflage; if he has a thermal imager you’ll need to adapt your techniques, but the basic aim is the same.

Related: Camouflage and Concealment: The Art of Staying Hidden

Hide behind things

A thermal imager is like any other sensor; it can’t see you if you’re hiding behind something that blocks the signal it detects. The thermal radiation you give off can penetrate some things that would hide you from visual detection, but it can’t penetrate everything. If you’re moving across country, use the ground. No imager can see through a hill or rolling ground, so if you can put terrain between you and it, you’re invisible. Solid walls will conceal you, too. Stud partitions or drywall won’t reliably block your body heat, and some military systems can see through a single layer of brick, but a brick cavity wall or masonry is enough to hide you.

Be careful with vegetation. Light brush or grass won’t block your body heat, but heavy undergrowth will. If you’re deep enough in the woods you’re also safe from detection – from ground level, at least. An airborne thermal camera, looking down, can see through a light forest canopy. On the other hand, old trees with a dense canopy can conceal you from all but the most sophisticated military imagers.

Block your body heat

If you trap heat, the imager can’t detect it. Unfortunately, if you trap all your body heat, you’re at risk of overheating and becoming a casualty. However, the less heat you’re radiating the closer the imager has to be before you stand out enough to be detected. Just wearing a field jacket instead of short sleeves can cut the imager’s range by five to ten percent, and every little helps. Bare skin stands out more clearly than clothing, so minimize it.

Some people have suggested that wearing a wetsuit will hide you from a thermal imager. It won’t. The problem is that the suit will quickly warm up until it’s at the same temperature as your body.

An oversuit made of space blankets won’t hide you either, but these lightweight sheets do have some uses. They reflect heat, and any that’s reflected back towards you won’t reach the imager to reveal your position. Turning the blankets into clothing has the same problem as a wetsuit; they’ll quickly warm up. If you use them as a liner in your shelter, however, they’ll cut down the heat that escapes and can slice a good chunk off the imager’s range.

Think about where and how you shelter. Under a tent or shelter half you’ll stand out clearly on thermal; in a cave you won’t. If you’re in the woods, a shelter with a roof of branches and dense brush will dramatically reduce the range you can be detected at; if you can put a layer of soil on top you’ll cut it even more.How To Hide From Thermal Vision Branch Shelter

In winter thermal imagers are extremely effective, because they’re scanning for warm objects on a uniform cold background – but you can turn that against them. Snow is a great insulator, so if you dig a snowhole in a drift, then shelter inside that, you’ll be very well concealed.

Match your background

It’s very difficult to precisely match your background as a thermal imager sees it; different materials radiate heat in different ways, and you’ll never be able to disguise yourself as a rock. However, temperature contrasts make things a lot more obvious. If your background is close to body temperature you’ll be much less obvious, and while you won’t be invisible the detection range will fall. On sunny days look for backgrounds that absorb heat, like brick walls or bare earth, and try to stay between those and locations where you think an imager is likely to be.

Use sources of heat. If you need a place to hide, and a nearby building has an air vent that’s pumping out hot air, sit under it. The whole area will be above ambient temperature, and that can help mask your body heat.

Stay near water, especially in warm weather. If there’s a lot of moisture in the air it will hold a surprising amount of heat, and this will help to reduce your contrast.

Your best chance of hiding in the open is against a confused background. On a uniform background like snow or an empty parking lot you’ll stand out clearly.

If there are lots of different materials, all radiating heat at different rates and wavelengths, the imager’s picture will be more confused and you stand a much better chance of blending in. Thermal imagers aren’t magic; they just look at the world in a different way. If the picture the operator is looking at is a mess you’re going to be much harder to pick out.

In an emergency, set things on fire. Multiple heat sources will confuse the picture and give you a chance of slipping away. And, while smoke generally won’t block the picture, if you burn the right things it can help. The military use white phosphorous or rubber-impregnated smoke shells to block thermal pictures, because they fill the air with burning particles and create a wall of heat that’s opaque to the imager. If you can burn stuff that throws off lots of soot and burning particles, that will seriously cut down the imager’s range. Old tires can fill the air with dense, hot black smoke. Shredded paper will put up burning fragments. The fires themselves will be very obvious, but the messy picture they create might give you the chance you need to slip away.

Use the crossover

There are two times in the day when thermal imagers don’t work very well; just after sunrise, and again just after sunset. These periods are called thermal crossover, and the change from day to night conditions dramatically reduces contrast in a thermal imaging view.

It’s very hard to predict how long thermal crossover will last. On a bright sunny day it can be a few seconds, which is useless to you, but if the weather’s overcast it can last several minutes. High humidity will extend the length of crossover, and so will wind. If you have your own thermal imager you can check to see if crossover is having an influence – but be aware that military imagers will overcome the effect faster than commercial ones.

A few don’ts

  • Wetsuits, drysuits and Arctic clothing won’t work
  • Lining your clothes with space blankets won’t work either
  • Thermal imagers aren’t like infrared security lights; moving very slowly won’t hide you
  • Hiding behind glass is not effective – and many military systems combine thermal and optical imaging, so they can see through glass anyway

There’s no doubt that hiding from a thermal imager is difficult. Don’t give up, though; with some knowledge you can reduce the sensor’s detection range, and that can give you the edge you need to stay concealed. A thermal imager isn’t an all-seeing, Godlike adversary; it’s just a camera with some special tricks, and it can be fooled.

You may also like:

invisible bph bannerHow To Disappear Completely When SHTF

H2O Dynamo – The Awesome DIY Device That Turns Air Into Fresh Water! (Video)

10 Reasons Why You Do Not Want to Bug Out

Spider Hole Tactics to Defend Against Looters

Fergus Mason
By Fergus Mason January 16, 2017 14:42
Write a comment


  1. AK Johnny 1 January 16, 15:55

    Dang…. I was hoping that some new clothing articles and such would be invented and put forth that would defeat these things. In a hostile situation, unfettered ability to be mobile would be quite an asset.
    Ah well…. Give it a few more years, eh? Some enterprising soul will figure out how to create either clothing or cloaks and such, to nullify these ungodly devices… lol

    Reply to this comment
  2. Wannabe January 16, 16:23

    Oh yea I got this one. Cover yourself entirely with mud and you won’t be detected. Just like in predator. If it works for Arnold it will work for you.😆 Lol!

    Reply to this comment
  3. jan January 16, 18:35

    while evaluating different camo designs, we noted that black and other dark colors which retained heat, were more visable via night vision than neutral colors.

    Reply to this comment
  4. WarDog January 16, 21:12

    No, no, no, you cotton-headed, ninny-muggins…
    Just close your eyes. If you can’t see them, they can’t see you, right?!?
    …maybe cover yourself with mud first, THEN close your eyes…

    Oh, I forgot to say: lol…

    Reply to this comment
  5. JC January 16, 23:49

    Probably impractical… what about a bunch of “instant” hot / cold packs, to change your obvious human outline, & your immediate environment, or leave a fake hot human shape, for “them” to concentrate on, while you egress ?
    It would appear that two mylar thermal blankets, with an insulated space between, (including the hot/cold packs) to produce irregular hot/cold areas, would be most effective, in conjunction with normal Camo to break-up the defining shape, which is the main goal… definitely, a “one time, short term, solution”…
    Unless, of course, it works… “stupid ideas”, AIN’T STOOPID, if they work!

    Reply to this comment
    • Leeroy Jones June 5, 12:34

      I use cheep heat packs occasionally to sight in my XP50 thermal. Stands out like dogs balls. So I can see some merit in your idea, but a decent thermal scope would revile your deception pretty quick I’d say….
      Cheerio from Australia.

      Reply to this comment
    • Prowess December 18, 08:00

      A decoy is always a great tactical asset. If you can’t fool the equipment, fool the asshole operating it!

      Reply to this comment
    • Dupin January 9, 01:31

      The concern I have with this is that the hot or cold packs will stand out greatly from the background radiant temperature, which will draw the user of the IR scope and those he’s directing, but won’t effectively hide you. It will alert them that someone is in the area which may intensify the search in that area. If you’re able to beat feet or otherwise un-ass the area quickly, it may be better to not draw their attention in your general vicinity. Situations vary, and I can see a few times where this may well work in your favor, but not the majority.

      Reply to this comment
    • Grama Pei March 24, 04:59

      Orrr, just go in a group and hug and those watchers will think you are octopi not human? 😀

      Reply to this comment
    • Here comes the tank February 15, 22:52

      You spread the ice/cold packs in a 50 yard radius and place multiple in a fight foot radius away from your position thus making it difficult to the operator your position and giving you the upper chance…. but then comes a tank and you can say goodbye to that idea cause them idiots shoot at everything hot.

      Reply to this comment
  6. Damien January 17, 00:40

    What about replacing the fabric of an umbrella with space blanket materiel, that would keep the materiel off your body so it won’t heat up, while still retaining the reflective qualities. Had the umbrella thought after thinking would it work to set a space blanket as an over head tarp, but wanted to move around

    Reply to this comment
  7. Damien January 17, 00:42

    What about replacing the fabric of an umbrella with space blanket materiel, that would keep the materiel off your body so it won’t heat up, while still retaining the reflective qualities. Had the umbrella thought after thinking would it work to set a space blanket as an over head tarp, but wanted to move around

    Any chance of moving the notify to follow up comment button a little further from the post button?

    Reply to this comment
    • Dupin January 9, 01:37

      If you know exactly where you would be viewed from, this might work. Mylar tends to be reflective material, so I’d line the inside of the umbrella rather than the outside to keep that to a minimum. Moving with it could provide a faint circular object in the IR scope, and if you’re not careful, show hot glowing feet or hands or head occasionally exposed from around the edges of the umbrella. However, the umbrella is quite portable unlike some other possibilities.

      Reply to this comment
      • thevillagegeek May 17, 05:32

        I had this idea, but with another layer of dark material on the bottom so you could use the umbrella without giving away the reflective layer. This is something you would use in combination with tree cover, other heat sources, additional improvised barriers and the like. I’m thinking that a layer in a backpack, combined with other things in the pack, might be a handy way to cut thermal signature if you compact yourself in a good location.

        Reply to this comment
  8. bobmouse55 January 17, 03:14

    I wonder how effective cold water or dirt piled on corrugated steel would be in deflecting aerial surveillance. Any thoughts and/or suggestions?

    Reply to this comment
    • FL Flatlander January 18, 03:18

      Regarding cold water:

      Start at about the 5:30 time mark.

      If you have a steady flow of it, properly directed, it could be useful.

      Reply to this comment
    • bobmouse55 January 20, 06:55

      Thanks FL Flatlander. I thought I would get some more serious answers here on this web page.. Looks like most of the respondents are juvenile libtards. Grow up boys and girls and if you don’t have something useful to contribute, please don’t waste our time.

      Reply to this comment
    • Dupin January 9, 01:45

      Dirt would definitely help. To work well, you need a good layer a few inches thick, so you need decent support for your corrugated steel. Better yet would be to have live foliage over your dirt, since the dirt itself will appear differently than foliage and a base geometrical shape will scream man-made and draw attention even to the visible eye. While the article is more specific to IR, you need to be hidden from IR, low-light and visible capabilities.

      Reply to this comment
  9. Grandpasaid January 17, 07:03

    I believe the umbrella with space blanket material would probably be the most practical and effective solution. You just open the umbrella towards the thermal imager, but you have to know where the thermal detector is located. For example we know from what direction, usually the sky, the rain is coming from, right ?

    Reply to this comment
    • Damien January 18, 08:54

      golf umbrella or fishing shelter umbrella? Big cover, still partially mobile…those fish won’t stand a chance! 🙂

      Reply to this comment
    • Byteme January 23, 15:06

      what about collapsible plastic cylinders to fill with dirt to put about your shelter and the thermal blanket with dirt and branches on top to get a full nights rest. The umbrella idea sounds as if it would work… anyone with one of the thermal gadgets to test ideas with? The need to keep your stuff light is very important.

      Reply to this comment
  10. KCK January 18, 22:16

    From all I’ve read, the reason the Mylar doesn’t work is because it will heat up when it comes in contact with the skin or heat source.

    What if you sandwiched it in the middle of a quilt? The batting and cloth would keep it from touching your skin (especially so since you’ll also be wearing clothing…hopefully LOL) This could be made into a hooded cape for movement.

    Hmmm.. I’ll have to try that out!

    Reply to this comment
  11. Deep January 19, 22:47

    Not sure if you seen but radiant barrier cloth works 100% .There are already companies selling them and giving the instructions away for free to anyone who wants to build one . I have two thermals and neither can detect anything .You can search on youtube to see the videos .Defeating Drones. I got my radiant barrier from a online company that sold it by the yard .

    Reply to this comment
    • Dupin January 9, 01:55

      I’m assuming this cloth is in a shade cloth type operation rather than being used as clothing for the reasons stated in the article. Is this a correct assumption?

      Reply to this comment
  12. Irritated January 19, 23:30

    Nice job stealing content from Tin Hat Ranch! What a tool! 1/2 this article and 2/3 of the photos are seriously poached from another member of the Prepper community. Just stop.

    Reply to this comment
    • BillH January 26, 22:16

      Agreed. A review of the material followed by a link would have been acceptable to all parties. But this is not. They didn’t even do a good job of creating a summary. This article makes it sound hopeless and thus pointless. The original article does not.

      Reply to this comment
    • Rocky August 22, 15:57

      Your right on this but frankly I don’t care where the information comes from as long as it saves patriot lives.

      Reply to this comment
    • Grama Pei March 24, 05:03

      hear here!

      Reply to this comment
  13. GittinSkinny May 8, 18:12

    Anyone seen the Cat s60 phone? I would sure like to see a review from a preppers perspective. It might be handy to use the technology too. And to learn the limitations.

    Reply to this comment
  14. Munga July 15, 09:45

    glass is king when it comes to thermal, infrared can see though it but not thermal

    Reply to this comment
  15. Windy February 5, 20:08

    Just fart continuously and any heat seeking rounds will be confused by the hot gas and veer off and miss you.

    Reply to this comment
  16. PHIL TRIMMER March 19, 20:37

    Make sure you make and keep a gilly suit to disperse you temp. signature.

    Reply to this comment
  17. Hop May 21, 20:13

    Oathkeepers video on YouTube: blocking thermal imaging

    Reply to this comment
  18. Briley May 22, 22:04

    I once worked with these devices as well as other detection and assessment equipment. Now, understanding that it was 20 years ago, this may not apply to the therma imaging devices currently available but the easist way I found to spoof them was with a stand-off shield made of corrigated cardboard. I could easily get within a few 10’s of yards before being detected; it works against passive infra-red devices, too.

    Reply to this comment
  19. Spike July 19, 17:35

    It would be nice to hear from people who actually have a thermal imager and hear what they have to say about their experimenting on this topic. I do like the umbrella idea but….I don’t have an imager.

    Reply to this comment
  20. left coast chuck July 20, 02:20

    I read somewhere that on a field demo of thermal imaging a USMC gunnery sergeant was listening intently to the sales rep’s spiel and spoke up and said, “Give me a half an hour and I can be in rifle range of you and you won’t see me with your device.”

    The sales rep assured him that it was impossible but go ahead and try.

    Twenty-five minutes later the gunny stood up fifty yards away from the demo group. He had used a ghillie suit over an umbrella and just inched up on them. They were busy chatting, depending on the thermal imager to detect him and not watching in front of them. They would have been DRT.

    Don’t know if that is a true story or not, but it sounds good.

    Reply to this comment
  21. TheShoot August 19, 12:44

    practice walking like an animal shouldn’t be to hard for you primates, wearing hooves on your paws and having antlers could help, practice makes perfect.

    Reply to this comment
  22. Sookie October 12, 09:52

    A shelter drapped over an uneven leanto.
    Made by sandwiching a wool blanket, Mylar blanket, then layers of branches.

    Reply to this comment
  23. Jungle November 8, 03:26

    Easy work for the robots they are creating now. Feels like the Terminator.

    Reply to this comment
  24. Mayhem November 16, 01:09

    I was hopping you would dive into “thermally”hiding a room or contents there in.

    Reply to this comment
    • Grackopolis February 10, 07:52

      Best method I have found for that is to cover your room/shelter/contents with earth and grow grass or other brush on top. Near impossible to detect unless your place is significantly hotter/colder than the ground you have covering you. If your ground is the same temp as surrounding ground, you have a winner.

      Reply to this comment
  25. Jimspip November 17, 00:29

    My neighbour has three thermal imaging cameras focused into two windows into my house. Will the heat lamp facing each one confuse what is seen when I move about?
    (for some reason he has to know where I am so he can leave and return unseen by me, don’t ask me why I don’t know)

    Reply to this comment
  26. King Porthos January 31, 16:17

    I was thinking a Ghillie suit with freezer packs interwoven.

    Reply to this comment
  27. pearler August 21, 14:44

    I have designed a system for this type of warfare .
    I wish I could share with yawl, but then it could be looked into and possibly a counter system designed to defeat my system .
    It is however a two way system .
    It detects and hides .

    Reply to this comment
  28. Redrum July 5, 18:24

    Cool mud

    Reply to this comment
  29. PredOr August 22, 14:49

    Just walk on all four to make it look like you are an animal.
    What about tin foil if you cover yourself with it?

    Reply to this comment
  30. Phil A Delphia September 26, 12:24

    I have a solution but I can’t sell it or market it. It’s my wife. If I hide behind her, you can’t see either of us. You see Satan, AKA my wife, has no heart. Without a heart, there’s no blood so there’s no heat. Her chest registers black with thermal imaging. The rest of her shows up as shades of gray and no, not fifty shades of gray. This has been tested and proven.

    Reply to this comment
  31. clergylady December 19, 04:52

    Interesting and worth thinking about.

    Reply to this comment
  32. Govtgirl December 19, 06:11

    Thank you for this article, Ferguson. I was not a subscriber back in 2017 so hadn’t read it before. It is an excellent introduction. I still thought infrared was the thing. You debunked the logical but incorrect solutions most people would initially come up with. Being out in the open is no good. I also think that many of the decoy ideas offered might backfire because they would look artificial and suggest someone was in the area. Appreciate the tip about the the thermal crossover periods which I have stored in my brain as the “Just Afters.” Anyway, you gave me a solid base for inquiry. Thank you.

    Reply to this comment
  33. Grackopolis February 10, 07:46

    I have used thermal imaging quite extensively. I can tell you that at night, (and in some cases day) staying behind glass works well. Thermal WILL NOT detect through glass. But, as the article mentions, during the daytime normal optics make glass a no-go. Glass reflects thermal radiation quite well, so to the viewer it becomes much like a mirror.

    Additionally, at night time when the air is cooler you will notice that areas with high thermal mass work well to mask you. Essentially, the more density and mass an object has, the more solar heat/mass it retains during sundown. This effect is noticed most in outdoor situations where it cools down at night. Rocks/stone/gravel in the evening/night will appear much hotter in thermal than the surrounding brush. This is because they take considerably longer to cool down from their surroundings. Additionally, thick brush and organic materials between you and thermal imaging create a great barrier. Think of materials as thermal walls/insulation. The more barriers you put between you and the viewer, the less it will pick up.

    A perfect camo will be highly insulated and emit no heat…rather, it will retain the same amount of heat as your identical surroundings. Wearing brush and foliage that extends off of you like a tree would help add to confusing imagery. But remember this. Something that emits NO heat or is, instead, very cold, can also stand out. Cold objects in thermal appear the exact opposite in contrast. …so if an imager is set to show hot as white, then cold appears stone cold black. Most imagers, like mine, use a weighted calibration that looks at a scene and then makes the average temp appear grey. …this means cold items are pitch black, and hot are white. The cold, therefore stand out just as much as the hot.

    Best advice I can give is to remember is this:
    AVERAGE does not stand out.

    Don’t think of being hot or cold. Instead think of being like your average surrounding…whatever that may be.


    Reply to this comment
  34. CHALK2 February 18, 04:31

    All of the jihadists who have used any of these techniques are now blowed up. It’s actually pretty comical watching them try to hide without the faintest idea it’s a UAV that just killed their homies and is now gunning for them.

    You can run, but you cannot hide.

    Your best option is to not become a target of a weapon/surveillance system that utilizes thermal in the first place. In other words don’t do dumb things, and live as the gray man.

    Reply to this comment
  35. City Chick February 23, 01:24

    A friend rented a thermal image device from the local Home Depot to check his home for drafts and areas where he might need more insulation or weatherproofing. He told me it worked great! He also told me that later in the evening when he was going back to return the device, he noticed that with it he could still see thermal tracks left by his wife’s and dogs footprints on the pavement outside their home over an hour after they had already went back in the house.

    Reply to this comment
  36. The Grim Crapper March 9, 08:18

    There are things that you can use to build a “ghost cloak” to hide from thermal imaging that actually DO work ! I have several of these and have tested them with commercial imagers (such as FLIR) . If you can find and buy radar netting that the military uses this should be used as the outer layer (think of wearing a large oversized Poncho made of netting like the base layer of a ghillie suit). I’m not sure exactly How this layer hides things from a thermal imager but it Does actually cut down the image by quite a bit ! Remember that any and all exposed skin will still show up easily on thermal imagers ! You can see through and easily breathe through this netting while wearing it so the hood should be removable from the full cloak but to be very effective your full face and hands should be covered by the netting (again think ghillie suit) . Other under layers of different materials will make these cloaks more effective but the radar camo netting should be what you start with to build your own ghost cloak .

    Reply to this comment
View comments

Write a comment