Effect of Urinary Sheath Use on Hydration Status of Fighter Pilots Under Severe Thermal Stress: An Observational Study.

Introduction: Fighter jet pilots may adopt a voluntary hypohydration strategy hours before take-off to avoid urinating in flight. This may favor sortie-induced dehydration and potentially increase flying errors. Since 2015, French pilots have used a urinary sheath (US) that appears to have resolved this problem.