Reminds me of the time I was in LT and chatting to one of the old Airlines of Tasmania pilots. He was telling me that the heated windscreen in their Mojave had failed and all the air ambulance pilots had been given a rocket by their Manager for daring to use it. Didn't they understand that windscreens overheat! He also told them that he was working through the incident and believed some one had left the windscreen heat on ovenight. The culprit when found out was to be sacked immediately!!