When I was just starting out as a young wild land fire fighter the 10 a.m. rule was policy in the suppression world of the Forest Service (FS). Simply stated it directed ALL suppression efforts be directed at the goal of containing the fire by 10 a.m. the following day. 10 a.m. is roughly the beginning of the next day’s peak burning period of critical fire behavior.
This meant if we broke a fire that you did not catch by end of shift you can darn well expect to be on it until your relief showed up the next day. At times that lead to 24 to 36 hours on the job.
Nowadays there exists the philosophy that they have to rest the troops overnight so they will be available for tomorrow. Minimal staffing during the night hours when the air cools, the relative humidity rises and the fire lays down. The very best opportunity to catch the fire small. Take note those troops that are “rested” overnight for the day shift tomorrow often spend the day watching the fire burn very actively and unable to take constructive suppression action during the peak burning period between 10 a.m. and 10 p.m. due to it being just too dangerous. No amount of acreage is worth anyone’s life.
To be fair (I guess) there are policies now that prevent following the 10 a.m. rule. There is a work rest “guideline” that for every 2 hours worked the firefighter has to be given 1 hour of rest and there is a 16- hour limit (minus meal times). Work 16 hours you need 8 hours off. If your day started at 0930 16 hours is sometime after midnight. You are shipped in to get rest. Sleeping thru 10 hours of cool, humid conditions when the fire is not as dangerous as in the day.
The whole concept about the fire laying down after dark and should be hit aggressively is a generalization. There are times when the fire does not lay down at night and fire behavior remains extreme all night. Any large fire will exhibit this behavior. However, there are many fires that could have been stopped during the night that now days they sit quietly at night just to blow up the next day.
The other 10 a.m. rule I grew up with was that if I did not get home until 10 a.m. the next day I better have been laid up in a hospital somewhere or my folks may put me there.