The most serious obstacle to overcome in present-day cardiorespiratory resuscitation is the necessity of opening the chest. This step of the procedure has always been a stumbling block, and no doubt has been one of the factors which retarded the development of resuscitation from 1902 to 1950. Only within the past six years has cardiac resuscitation become an acceptable procedure in the operating room. Finally, resuscitation emerged from its underground tunnel of despair to be accepted as a therapeutic measure with potential new horizons for overcoming temporary death and restoring life. Experiments now indicate that closed-chest resuscitation can become a practical reality. Experience leads us to believe that the time has arrived when cardiac resuscitation must be included in certain cases of sudden clinical death (relative death10) outside the operating room, and possibly outside the hospital. For example, resuscitation is now feasible for those persons facing impending death from