Military training aims to prepare personnel to perform under life-threatening conditions, often in sweltering heat or freezing cold, wearing clumsy protective garments, in situations that are highly ambiguous, and where individual soldiers, sailors, or airmen have little apparent control over their fates. Modern military training incorporates many stressors in an effort to "harden" personnel for the rigors of combat; however, much of that training is nonspecific with respect to stressors and uninformed with respect to predicted performance enhancements. In their review of 35 articles and books on combat stress, Michel and Solick ( 1983) found that neither the exact amount of performance degradation nor proof of the nature or source of those degradations could be determined from the literature.