METHODS	After approval of the local Ethics Committee and written informed consent , four forced-air warming systems combined with upper body blankets were investigated in a randomized cross-over trial on six healthy volunteers : ( 1 ) BairHugger trade mark 505 and Upper Body Blanket 520 , Augustine Medical ; ( 2 ) ThermaCare trade mark TC 3003 , Gaymar trade mark and Optisan trade mark Upper Body Blanket , Brinkhaus ; ( 3 ) WarmAir trade mark 134 and FilteredFlow trade mark Upper Body Blanket , CSZ ; and ( 4 ) WarmTouch trade mark 5800 and CareDrape trade mark Upper Body Blanket , Mallinckrodt .\