In FIGS. 4A-4D, a mechanism to releasably retain the upper body thermal blanket 51 as a separate element may include a plurality of islands of pressure sensitive adhesive material, hook and eye material, snaps, or other equivalent elements as described above in connection with FIGS. 3A and 3B. A mechanism to releasably retain the upper body thermal blanket 51 as an element formed integrally with t