Over the past fifty years the University of Montana, in conjunction with the United States Forest Service, has been investigating the job demands of wildland firefighters. This document is a combination of three research projects with a connection of health and safety of wildland firefighters. Smokejumpers are unique because they parachute into remote fires and are used primarily as initial attack wildland firefighters. Studies have shown that initial attack is the most energy intensive part of wildland firefighting. The first study identifies maximal and sustainable aerobic fitness possessed by US Smokejumpers. The maximal aerobic characteristic of US smokejumpers is well above average aerobic fitness compared to the general population, and sustainable aerobic fitness is similar to the fitness required for fire line digging during initial attack on wildland fires. There is also no difference between gender and age groups. The second study identifies the relationship between smokejumper core critical tasks (fireline digging, packing loads over 85 lbs, and repetitive lifting/carrying) and the current physical training (PT) test. The smokejumper PT test uses push-ups, pull-ups, sit-ups and a 1.5 mile run to determine if individuals have the minimal fitness required for successful job performance. This study found a relationship between push-ups, pull-ups and the 1.5 mile run to smokejumper core critical tasks, but there was no relationship with sit-ups. While physical fitness helps to mitigate certain risks associated with fire suppression, it alone is not enough, so personal protective equipment (PPE) is also used maximize safety. The majority of specifications used in construction of this equipment considers only the external environment and does not consider the individual as part of the environment. The third study evaluated the thermal stress on the human body with three typical configurations of personal protective equipment. The use of increased layers of PPE was found to increase the thermal stress identified by body temperature and physiological strain index. The use of two layers of PPE compared to one decreased potential work time by half before a critical core temperature was reached.