We offer them as a last resort if the furnace can't be repaired or replaced that day, but usually its only if they are getting us to do the work as in they paid for the parts that need ordered or replacement is sold and scheduled. Not required but we always try to go above and beyond.
since I started doing service work, i have worked at a company that never gave them out. Then I went to a large commercial company, where i was in energy and automation and the opportunity never came up. The last company did kept me mostly on military base but did have a space heater in every service van. So I am on my own now and was thinking maybe code changed. I do get them to initial the sentence about why I shut it down and what the dangers are of turning it on plus a flyer and quote to replace before I leave. I believe code is initial and quote but started wondering about the temp heat. Now I know.