Under extreme and stressful conditions, humans don’t rise to the occasion, they sink to their training. Extreme environments are characterized as those situations which place a high demand on the physiological, affective, cognitive and/or social processing resources of the individual. Extreme environments strongly perturb the body and mind, which in turn initiate complex cognitive and affective response strategies. Different types of extreme environments may share some aspects but can also have unique demand characteristics. For example, exposure to the cold and isolated environment of an Antarctic expedition may result in extreme social and sensory deprivation, whereas exposure to military combat operations may entail extreme sensory overload. An individual’s cognitive and affective responses are as varied as the different types of extreme environments. There is little doubt that rigorous physical training has the capacity to strengthen and build an individual’s cognitive and affective response to stressful conditions and extreme environments; however, research suggests that it needs to include building mental as well as physical strength as its primary goals. What are you doing to build your mental toughness?