Defeat Thermal Imaging , page 1

"
Simple tactics
Nets and smoke are the hi-tech solution to TI. But even the most unsophisticated forces can evade TI by intelligent tactics and good SOPs. If you follow the basic rules of fieldcraft, you will go a long way towards defeating TI. Avoid open spaces and skylines by day or night, and use dead ground and cover when you are on the move. A patrol, exactly spaced, moving across the middle of a field at night, will stand out dramatically against the cool grass.
TI can see heat patterns through conventional camouflage nets and vegetation like thin hedges and scrub. But it is not an x-ray eye. Buildings, walls and even thick vegetation will conceal men and vehicles.

TI is most effective where the enemy is easily identified, for instance in the desert, open grassland, or the arctic. The most difficult is a built-up area, which may contain civilians and their vehicles. Heat patterns here will be enormously varied, with some buildings showing warm, and a confusion of blobs of heat from individuals, cars, trucks and even livestock. In this environment, soldiers must avoid behaving in ways that act like a signature - like forming a queue for food, parading in three lines, or even using the slow skulking walk of men moving tactically.

Garages, barns and even multi-storey car parks will help conceal APCs and tanks, which can be deployed as an armoured quick reaction force (QRF). Houses can be prepared for defence and will not only offer protection against small arms and shell fire, but also concealment from TI and other observation systems.

On the run
The techniques and equipment described above will assist the soldier, but can the fugitive use them? Clearly camouflage nets and IR smoke will not be used by the man on the run. But the fugitive can employ simple evasive tactics which will go a long way to negating the advantage of a pursuing force equipped with TI.
In car or on foot, the evader should aim to blend into the thermal clutter from other people or vehicles. Busy towns and cities are therefore better than open countryside. If a car is being followed by a TI-equipped helicopter, underpasses, tunnels and even cuttings may offer cover and perhaps the chance to change vehicles. If the driver suspects that he is under surveillance, he should not behave in a way that will attract attention - erratic, slow or excessively fast driving is bound to attract attention.

For the evader on foot, a crowd or any solid cover from above or the side, will give a few moments in which he can shake off the 'eye in the sky'. TI does not perform well in falling rain, snow or sandstorms, and search aircraft may be reluctant to fly in these conditions anyway. An added benefit is that snow or sand covers tracks and muffles noise. Finall, bad weather makes guards and search teams less alert.

As with any observation system, TI is only as good as the operator. As ranges increase the image becomes attenuated - in simple terms, the target becomes less distinct on the scope, and appears as an indistinct hot blob. If this blob behaves like a law-abiding civilian blob, the operator will switch his attention to other areas.

In two words, one of the best ways to defeat thermal imaging is 'act natural'.
"
If you don't mind, I'm not listing the source. Also, except in cold weather, Pine trees give a heat signature close to a human (excellent overhead cover). When Afghans hear choppers overhead doing sweeps, they use wool blankets they carry as quick TI camouflage. Don't wear the blanket or it will heat up, carry it low on your pack and throw it over you when needed. I guess I need to specify don't do this on top of a hot rock or you will stand out as a black spot.

If you camp or go to the "field" buy a reasonable quality IR thermomater and tag objects (bushes, trees, lowspots/highspots, structures) and compare to the wool blanket you now carry to get experiance in blending in to your environment thermally.