Hyperbaric environments, such as those employed in deep diving systems, present unique problems for designers of environmental control systems. This paper starts with a brief discussion of the effect of pressure on heat transfer between man and a hyperbaric gas. A mathematical model for human response to thermal stress and exercise is then described in general terms. Finally, two applications of basic principles discussed in the first sections are presented. One example involves environmental control in a welding habitat at 31 atmospheres, and the other concerns evaluation of survival systems that must provide 24-hour protection for divers who are trapped in an isolated bell on the ocean floor. By judiciously combining theoretical analysis with experimental studies, one can make valid judgements about these rather complex systems which are very difficult to evaluate directly.

Units: SI