I'm looking for the console or command line that will eliminate Flamethrower overheating OR reduce or eliminate the Flamethrower recovery time.
I posted the codes I have found for unlimited ammo and some other commands...

Conso le commands you can use in co-op and single player without booting the "devmap" first
sf_use_bw 1 = Black and White movie mode
sf_use_ignorea mmo 1 = Infinite ammo
sf_use_invert 1 = Photo negative mode
sf_use_chaplin 1 = Silent movie mode

To boot a developers map and use all cheats:
devmap [map name] = starts the selected map in developer mode and you can use god mode and all cheats.
god = God mode
demigod = Double health

Console commands that may or may not require that you be in a "devmap" to use.
I haven't tried them.
notarget = Disable AI
mapname = List maps
give all = All weapons
noclip = No clipping mode*

*For those that don't know: (I didn't until recently)
No Clipping means that you can walk through walls and certain barriers. It has nothing to
do with ammo clips or reloading. Use the unlimited ammo command for unlimited ammo and no reloading.

I don't know if it will allow you to walk outside on a zombie map or not, I haven't tried
it yet. For all I know, it may allow the zombies to walk through the barriers also, so I would try
it out on a lower level.