Winter stack effect can deliver toxic fire gases to the upper floors of a building. Particles, which are smoke, may drop out leaving pure odorless, tasteless, deadly CO. This killed two FDNY members on an upper floor of a high rise with a fire in the basement. The elevator operator died in his car.
Personnel searching upper floors should carry a CO detector so as to activate their SCBA when indicated, and be prepared to deal with unconscious casualties.
Summer stack effect reverses the airflow since the colder air is now inside the structure. It can make several floors below the fire untenable for the operations floor.
There is a full discussion of stack effect in BCFS3, pages 481-5. Some additional information is available on request to Fbranniga@comcast.net
ICE ON THE GROUND
It appears that some fire departments are surprised every winter when water freezes underfoot. They then think of getting sand and grit.
Write a SOP for dispatchers reminding, "In freezing weather, order sand and grit to the scene as soon as a working fire is declared".
Attention Maryland firefighters. I will be giving three programs at Maryland Fire and Rescue Institute in February, April and June. Call MFRI for details.