This paper by Hancock and Warm (1989) explores the effects of stress on sustained attention, a critical aspect of human performance in extreme environments. The authors present a dynamic model that integrates the three components of stress: input stress, adaptive responses, and output behavior. Input stress is defined by environmental factors such as noise and temperature, while adaptive responses involve the individual's physiological and psychological mechanisms for coping with stress. Output behavior reflects the individual's performance efficiency, which can be influenced by both psychological and physiological factors. The authors argue that sustained attention itself is a significant source of cognitive stress, as it demands high levels of alertness and attention. They review existing literature on the effects of noise and temperature on vigilance tasks, noting that while temperature has clear and consistent effects, noise remains less predictable due to the lack of a clear physiological analogue and the complexity of human responses to continuous noise. The dynamic model proposed by Hancock and Warm suggests that stress can be represented as a vector in a multidimensional space, with input stress vectors summing to define points on a manifold. This manifold illustrates the progression from stable to transitional to dynamic instability states, reflecting changes in psychological and physiological adaptability. The model emphasizes the importance of understanding the interplay between task demands and environmental stresses, particularly in complex and dynamic environments. The authors conclude that a comprehensive understanding of stress and performance requires an integrated approach that considers the specific demands of the task and the individual's ability to adapt. They highlight the need for further research to develop more precise models and predictions of stress effects, especially in the context of sustained attention tasks.This paper by Hancock and Warm (1989) explores the effects of stress on sustained attention, a critical aspect of human performance in extreme environments. The authors present a dynamic model that integrates the three components of stress: input stress, adaptive responses, and output behavior. Input stress is defined by environmental factors such as noise and temperature, while adaptive responses involve the individual's physiological and psychological mechanisms for coping with stress. Output behavior reflects the individual's performance efficiency, which can be influenced by both psychological and physiological factors. The authors argue that sustained attention itself is a significant source of cognitive stress, as it demands high levels of alertness and attention. They review existing literature on the effects of noise and temperature on vigilance tasks, noting that while temperature has clear and consistent effects, noise remains less predictable due to the lack of a clear physiological analogue and the complexity of human responses to continuous noise. The dynamic model proposed by Hancock and Warm suggests that stress can be represented as a vector in a multidimensional space, with input stress vectors summing to define points on a manifold. This manifold illustrates the progression from stable to transitional to dynamic instability states, reflecting changes in psychological and physiological adaptability. The model emphasizes the importance of understanding the interplay between task demands and environmental stresses, particularly in complex and dynamic environments. The authors conclude that a comprehensive understanding of stress and performance requires an integrated approach that considers the specific demands of the task and the individual's ability to adapt. They highlight the need for further research to develop more precise models and predictions of stress effects, especially in the context of sustained attention tasks.