While associated risks to health and safety are well-documented, the goal of this Research Topic is to shift the focus to potential solutions and gather novel findings on how to stay healthy and maintain performance under challenging environmental and working conditions. Of particular interest are works in the following areas: - Strategies to improve/maintain health and safety in temporally challenging environments and working conditions, such as shift/night work, irregular/flexible work hours, home office. - Strategies to improve/maintain cognitive performance, fatigue, and duty-readiness in challenging operational environments, such as spaceflight, aviation, emergency/rescue services, hospitals, maritime and military operations. - The role of individual factors in maintaining health, safety, and cognitive function under challenging environmental and working conditions