I am looking into a sunlighten sauna. They offer basswood which is hypoallergenic and are low emf. I was concerned about
the wood as well because I don't want to be inhaling nasty chemicals. Betterhealthguy uses this brand and has given it good reviews. This isn't a portable sauna though. They offer financing which makes it a bit easier to handle financially.
www.sunlighten.com/product/signature-i/