Medical History Taking/methods; Military Medicine/methods; Military Personnel; Physical Examination/methods; Tropical Medicine/methods; Dehydration/diagnosis; Dehydration/etiology; Dehydration/therapy; Diagnosis, Differential; Exercise Tolerance; Female Urogenital Diseases/diagnosis; Female Urogenital Diseases/etiology; Female Urogenital Diseases/therapy; Fever of Unknown Origin/diagnosis; Fever of Unknown Origin/etiology; Humans; Infections/diagnosis; Infections/etiology; Infections/therapy; Jaundice/diagnosis; Jaundice/etiology; Lung Diseases/diagnosis; Lung Diseases/etiology; Lung Diseases/therapy; Male Urogenital Diseases; Morbidity; Physician's Role; Problem Solving; Skin Diseases/diagnosis; Skin Diseases/etiology; Skin Diseases/therapy; Tropical Climate; United Kingdom