· Sub-zero temperature has a negative effect on both the performance and storage capacity for nickel cadmium batteries utilized by many 8mm video recorders and thermal imaging cameras. Be certain that the batteries are fully charged, and that you have fully charged back up batteries available prior to the field investigation commencing.

· As with any cold weather activity, comfort is the key. Multiple layers of down or gortex is recommended. Reversible white/brown camouflage parkas and one-piece multi-pocketed suits have proven highly effective. The neoprene type fingerless fishing gloves maintain an acceptable comfort level, without negatively affecting the dexterity needed to operate your equipment.

· A pre-surveillance of the site to be surveilled utilizing thermal imagery is imperative. Mobility is severely affected in deep snow, and snowshoes may be required. Regardless, be cognizant of the fact that you will be leaving tracks, which could be detected by the suspect. Your point of entry/exit in the area is critical, and aerial thermal imagery may be necessary.

· Be aware of the affects of snow and ice on your thermal imagery picture. Falling or blowing snow will negatively affect the quality of the thermal imagery picture, requiring you to get closer to your target structure. Take into consideration the reflective properties of ice, and the absorptive properties of snow when assessing your findings.