High levels of acute stress increase risk-taking and limit objective Situation Awareness (SA), actual knowledge of what is around you. Little research, however, has been directed toward understanding how stress influences subjective SA, an individual's assumption of their objective SA accuracy. The present experiment uses newly developed methods for highly controlled manipulations of stress, and newly designed measurements of risk-taking in a complex combat simulation. Results of this research indicated that high levels of acute stress may lead individuals to be overconfident in their SA and take more risks. Results are discussed in terms of their importance for individuals who require adequate SA in order to perform occupational tasks effectively, such as air-traffic controllers, pilots, and military personnel.