As the Atlas ICBM entered service with the USAF in the late 1950s and early 1960s, there were numerous design changes taking place rapidly that would have to quickly disseminated from engineers at the Convair plant in San Diego where the missile were produced to Convair engineering liasons in the field that were assisting the USAF in standing up the Atlas ICBM force at bases throughout the country.
In most cases the changes being done flowed out from Convair and into the field. In on case, however, some inventive USAF base crew came up with fix that while ingenious, was potentially dangerous. At Francis E. Warren AFB in Cheyenne, Wyoming, the crews were having trouble with a water line that serviced an Atlas launch pad. It would freeze over easily due to the proximity of a liquid oxygen fuel line combined with the extreme winters in that part of the United States.
Base personnel built a wooden box around the problematic water line and filled it with horse manure. As the manure decomposed, it gave off heat that kept the water line from freezing. However, manure also made a great fuel source that combined with liquid oxygen could have had potentially explosive results. This was noted by a Convair field engineer who had it removed and being diligent, sent a memo back to Convair-San Diego about a change to not enact!
Source: Atlas- The Ultimate Weapon by Chuck Wallace with John Powell. Apogee Books, 2005, p71-72.