Thermal warfare is the consequence of the mass diffusion of IR optics on drones, rifles and vehicles. Every human body, every engine, every hot barrel is an IR beacon. This chapter describes thermal signatures, defensive mitigation principles and concealment techniques. It does NOT contain target acquisition or offensive IR procedures.
What a thermal sees
A thermal imager detects infrared radiation emitted by every object above absolute zero. It is not amplified visible-light night vision (I²) — it is a completely different band, temperature-based.
- Common band: LWIR (Long-Wave Infrared, 8-14 μm) for passive thermal imaging
- Alternate band: MWIR (Mid-Wave Infrared, 3-5 μm) for advanced military systems
- Typical resolution: 320×240 to 640×512 pixels on commercial drones (Mavic 3T, Autel 640T)
- Military resolution: 1024×768+ on advanced platforms
- Human detection range: 500 m - 2 km depending on sensor and thermal background
- Critical point: distinguishes ΔT (temperature difference) between object and background, not absolute temperature
If you are warmer (or colder) than the background, you are visible. Even in daylight. Even under thick vegetation if the thermal cover is incomplete.
Typical thermal signatures
Knowing your signatures is the first step to reducing them. Every kit element has its own signature.
| Source | Thermal characteristic |
|---|---|
| Human body | Face, hands, neck at 30-35°C — hotter than almost any winter background |
| Rifle barrel after firing | Peak 100-300°C, visible for minutes |
| Vehicle engine | Peak 80-120°C, visible km, cools in 30-60 min |
| Exhaust | Peak up to 600°C, long-range IR beacon |
| Fire / heater | Intense source, betraying even when screened |
| Recent footprints | Feet on grass/dirt leave signature for 5-15 minutes |
| Recently parked vehicle | Residual thermal shadow on ground beneath |
Thermal concealment — principles
Reducing signature does not mean eliminating it — it means blending with the surrounding thermal background. The principle is equalisation, not isolation.
- Low-emissivity materials: mylar blankets, IR-defeating tarps (thermal ghillies), dedicated technical fabrics
- Thermal mass: earth, rocks, wood — natural buffers, reduce ΔT when interposed
- Water: less IR-penetrable but effective only if complete (light moisture is insufficient)
- Vegetation: dense wet foliage significantly reduces, dry leaves little
- Distance from sensor: thermal resolution degrades fast, dispersion + distance helps
- Timing: dawn and dusk invert thermal contrast (crossover) — exploit it
Wool blanket, standard jacket, polyester tarp barely reduce. A good thermal sees through them. The difference is made by dedicated IR-defeating materials or natural thermal mass.
Individual thermal defence
- Cover face and hands (hottest zones) in cold environments — bandana, gloves, IR-defeating balaclava
- Operate low, close to cold thermal mass (stone walls, earth, snow)
- Brief movement, halt in covered position — movement is doubly visible (signature + trail)
- Avoid carried heat sources (portable heaters, fires) in drone observation zones
- After firing: move fast — hot barrel + IR flash locates you for minutes
- Sleep system: do not isolate in a warm tent in thermal flight zone — use buried bivvy
- Smartphone, batteries, warm devices: shielded or off during stalking phase
Vehicle thermal defence
- Dedicated thermal covers (Saab Barracuda MCS or improvised equivalent)
- Positioning under dense vegetation, not only for visual but for thermal
- Engine off as soon as stopped — residual heat is visible 30-60 minutes
- Exhaust shielding (coolers, deflectors, metal screens)
- Dispersion: two vehicles close together form a double signature recognisable as a unit
- Fresh branches on hood: partial reduction, replace every few hours (drying)
Terrain and weather
Terrain and weather conditions radically change thermal visibility. Understanding this means choosing when and where to move.
- Heavy rain: degrades IR thermal — mobility window
- Dense humid fog: significantly reduces thermal range
- Fresh snow: very cold background, increases contrast on warm bodies
- Low sun (dawn/dusk): thermal crossover, landscape is thermally 'flat' — stalking window
- Cold clear night: maximum thermal visibility, avoid exposed movement
- Sun-heated ground: after sundown radiates for hours, can mask signatures on warm background
Common mistakes
- Believing visual camo = thermal camo (no correlation)
- Covering only with standard clothing against advanced thermal optics
- Smoking in exposed position — cigarette at 700°C, beacon kilometres away
- Idling engine to "stay ready" — persistent signature
- Grouping under a tree for a break: human cluster = huge IR blob
- Underestimating a Mavic 3T with thermal sensor 640 — commercially available
Lessons learned Ukraine
On the 2024-2026 front, thermal is ubiquitous: Mavic 3T, Autel EVO II Pro 640T, 'Baba Yaga' night drones with FLIR, Russian IRBIS optics and PNV-10T. The shared operational rule: move at night only covered by terrain, in dispersion, with chosen timing (rain, fog, crossover) or under dedicated thermal covers. Vehicles are dead if stationary in the open > 30 minutes in thermal flight zone. The difference between surviving and lost units is almost always in thermal discipline — covers, dispersion, time selection, engine cooldown — more than in top-tier kit. A well-used mylar blanket beats a poorly-used modern vehicle.