This cluster of papers focuses on the occupational health of emergency responders and military personnel, particularly addressing issues such as back pain, injuries, physical fitness, load carriage, respiratory health, and cancer risk associated with occupational exposure. The research covers a wide range of topics including physiological, biomechanical, and medical aspects of load carriage, cardiovascular disease in firefighters, musculoskeletal injuries in adolescents, and the impact of firefighting activities on respiratory health.