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When Do You Use a Thermal Scope: All You Need to Know

L.p. Brezny | Updated February 25, 2024 | Why You Should Trust Us | How We Earn Money
cover photo of when to use a thermal scope showing a scope, article title, and logo

With thermal scopes becoming increasingly popular, many in the shooting community are asking questions about their functions, like: when can they be used? Is it similar to a normal scope? How do you even use one?

And fair, because if you’re just hearing about it, this tech can be understandably alien to anyone.

But don’t worry, here’s all you need to know about thermal technology on your guns to get ahead and become familiar with the tech fast.

When Do You Use a Thermal Scope?

You can use a thermal scope whenever you want to, as they’re operable during the day AND night.

However, bear this in mind: thermal scopes see heat. Sounds obvious, but what we mean is that in really hot weather (think summer in the desert), a thermal scope may not work very well for two reasons.

  1. If the scope itself gets too hot, it simply won’t work. Temps over 120°F may affect the performance. As the heat increases, the scope’s ability to work will continue to drop.
  2. If the surroundings are the same temperature as your target, the scope won’t be able to see a difference.

On the flip side, thermal scopes work well in cool and cold weather, but the scope might also not work if it gets too cold. A good rule of thumb is thermal rifle scopes usually have a low operating temperature of -20°F. Depending on the brand, that temperature could be lower or higher.

Common Uses

The most common use for a thermal gun scope is night hunting. Varmint hunters lead the list, with coyotes being their top target (yotes are active at night, especially in places where they are hunted hard). 

And turns out, wild hogs are becoming a major target for night hunters too. If you didn’t know, feral bacon is actually incredibly smart, and they learn to avoid traps and feed at night to avoid hunters. They also spook easily when seeing a light, but since thermal scopes don’t use light, hunters can ambush the highly destructive animals during the night.

Daytime hunts with a thermal scope are also on the rise because of their beneficial abilities, like seeing through fog, light rain, and sparse bushes (they cannot see through trees and heavy foliage). 

Now, this is handy because your target can’t use natural camouflage to hide. Since the scope picks up heat sources, the natural browns found on many critters won’t hide them, making tracking the target as it moves through the woods all the easier.

Also, a handheld thermal device is great for tracking something you’ve already shot. Bow hunters who have to track a blood trail will find this handy as blood spots will appear as hot (as long as you get on the trail before the blood cools down to the ambient temperature). (1)

Where It’s Legal

Hold up! Before taking your thermal to the field, make sure it’s legal to use for where you are. 

California currently doesn’t allow hunters to use a thermal scope on a gun at any time. However, other states have varying restrictions on what you can hunt with them and the permitted time of day for its use.

These regulations are rapidly changing, particularly where wild hogs are concerned. So, check with your state’s wildlife agency for the most current regulations.

How Do You Use a Thermal Scope? 

A thermal gun scope functions largely the same as a traditional gun scope. You still have to attach it to your gun and sight it in. But what’s different is that it has to be switched on, needs batteries to operate, and sees heat instead of visible light.


Before buying a gun’s thermal scope, make sure you can mount a scope to it. Some handguns and shotguns may need extra work from a gunsmith before they can support optics. But nearly all rifles have a way to attach an optic.

rifle scope on camouflaged background

This Mossberg shotgun barrel is cantilevered, meaning it has a rail on the barrel to attach an optic. So, no gunsmithing needed.

Now, some scopes come with an integrated mount.

image of a Thor
This ATN ThOR has an integrated mount to attach to your gun’s Picatinny rail.

To mount some scopes, you need to buy rings.

Quick release cantilever scope mount product image on white background
Example of Rifle Rings

This thermal scope needs rings to mount to a gun, but luckily, there are some scopes like this one that offer package deals that include a single-piece ring setup to make purchasing easier.

Sight In

With your scope mounted, you now have to sight it in. The process is the same for thermal and traditional scopes, with one exception: a thermal scope needs help to see the target.

For this, you can tape pieces of aluminum foil to a standard target or buy one of the new thermal targets that are ready to shoot right out of the pack.


Before you head out to hunt, it’s best to learn how to use the scope’s video recording. That way, you’ll be familiar with the function and can deftly record your hunt to enjoy later at home.

When Is a Thermal Scope Better Than Night Vision?

In almost all circumstances, a thermal scope is better than a night vision scope. And here’s why:

  • Thermal can be used during the day. Most night vision can’t.
  • Thermal rifle scopes can “see” heat sources at 2,000 yards. Night vision is typically good to 100 yards or so.
  • Thermal scopes can track heat sources, like blood on the ground, after the target runs. Night vision doesn’t have this ability.

However, night vision does offer something thermal can’t. Night vision can see everything – within range, of course – regardless of the temperature and shows a level of detail a thermal cannot. (2)

When Is the Wrong Time to Use a Thermal Scope?

The three times it is wrong to use a thermal scope are:

  1. When it is illegal or not allowed.
  2. When the temperature is too hot.
  3. When the temperature is too cold.

How Do Thermal Scopes Work?

To find out exactly how do thermal scopes work, check out our full article on the subject. We explain everything you need to know!

Can You Use Thermal Scope in Daylight? 

Can you use thermal scope during the day? Well, yes, because a thermal image relies on heat sources, not light. 

For instance, if you hunt coyotes in the middle of the day in the western deserts, the landscape could be as hot as the critter, so seeing the difference may be hard. When the outside temperature is lower than a yote, the thermal will capture the difference in heat sources.


  1. Outdoor Life, 4 Reasons to Own a Thermal Scope, retrieved from https://www.outdoorlife.com/reasons-to-own-thermal-vision-scope/
  2. Optics Planet, Why You Should Buy Thermal Scope Over Night Vision, retrieved from https://www.opticsplanet.com/howto/why-you-should-buy-thermal-scope-over-night-vision.html

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