I wonder if anyone else here has thought about buying a bed canopy?
http://www.emfields.org/shielding/canopies.asp
The site has a sleeping bag too which would make it much cheaper but you would need to use the head cover.
http://www.emfields.org/shielding/canopies.asp
The site has a sleeping bag too which would make it much cheaper but you would need to use the head cover.