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William Sim, a Fire Service Station Officer in Lanarkshire, says firefighters can
get into trouble when they try to retrace their steps in a smoke-filled building (GB2345850).
Although firemen lay guidelines, they can become disorientated. Sim proposes a guideline
with clamp-on rings along its length, each with springy spines protruding at an angle and
pointing like arrowheads in the direction of safety. When the firefighter moves their hand
along the line, the spines collapse if it’s in the right direction. If in the wrong direction, they
feel an odd sensation in the hands, even through gloves.