Firefighters in breathing apparatus searching through a burning house for possible occupants. The fire is blazing out of control and the firefighters are working in temperatures in excess of 1000 degrees centigrade. On their tunics are right angled intrinsically safe torches. There are also an A.D.S.U., an automatic distress signialling unit, which is part of their B.A. sets. This unit emits a very loud whistle should the firefighters remain motionless for a short period. Therefore, if they... more »
