TM 9-2320-209-10-1 SECTION III. OPERATION UNDER UNUSUAL CONDITIONS 4-20. SCOPE. Extremes of temperature, humidity and terrain conditions require special operating procedures. Instructions for operating under these unusual conditions are con- tained in this section. a. Refer to FM 55-30 for instruction on driver selection, training and supervision. b. Refer to FM 21-305 for special driving instructions for operation of wheeled trucks under unusual conditions. 4-21. GENERAL. When operating under unusual conditions, pay particular attention to all gages and indicators for signs of trouble. 4-22. OPERATION IN EXTREME COLD WEATHER. a. General. Extreme cold weather will cause: (1) (2) (3) (4) that will burn. Lubricants to thicken or get hard. Batteries to freeze and keep from supplying enough current for starting. Electrical insulation to crack and cause short circuits. Fuel not to vaporize and mix with air to form a combustible mixture, for starting, b. Related Publications. Refer to the following for information relating to operation of a truck in cold weather conditions. FM 31-70 Basic Cold Weather Manual FM 31-71 Northern Operations FM 90-6 (HTF) Mountain Operations FM 9-207 Operation and Maintenance of Army Materiel in Extreme Cold Weather (0° F to -65° F) WARNING FM 9-207 contains general information which applies to all Army materiel. This information must be considered part of this manual. Approved practices and precautions must be followed for safe cold weather operation so that personnel will not be injured or equipment damaged. c. Winterization Kits. Special winterization equipment is provided in kit form when protection against extreme cold (0° F to -650 F) is needed. (1) Refer to para 4-16 for hot water personnel heater kit operating instructions. (2) Refer to para 4-17 for artic winterization kit operating instructions. 4-404