Heat while rehabbing w/o utilities?

[Stone Teran]

What temporary heat source should I use while rehabbing an apt building in the winter?  No utilities are turned on.  I like propane portable heaters but I'm concerned about CO poisoning.  Is that the customary temp heat source people use or is there a better way?

[David D Painter]

In the past I have always been able to easily get temporary power. Sometimes it required a temporary pole.