I did a search to find a simple build at home version of the oxalic pipe vaporizer, but all the links no longer work. Has it become against the law to build one for emergencey use? I want to order the JB200 but until I have the funds avaiable will need to do something else. Anyone have a good link to one I can build and use for this fall before it gets to cold. I'm worried that by the time I can get the JB200 it will be to cold around here. I believe it must be used above freezing?