Windows Cleaning Supplies Glasgow
The man uses one hand to cling to the building, while using the other to wipe the windows (SWNS)
Barry McLauchlan, 22, who was working on the opposite side of Caird Drive, Glasgow, recorded the terrifying moment on Monday morning.
The labourer, from Hamilton, South Lanarkshire, said: "I was just working away and looked across the street. I noticed this window cleaner.
"I thought nothing of it, but the more I stared I noticed he wasn't wearing any safety equipment. There was no harness or safety aids.
"I was shocked. I was fearing more for his life than he was."
The man doesn't have any safety equipment while cleaning the windows (SWNS)
The Health and Safety Executive (HSE), which regulates the workplace, said it could not comment as the man may have just been a member of the public.
But a spokesman added: "Falls from height are one of the biggest causes of workplace fatalities and major injuries, and we would hope anyone working at height took necessary precautions to prevent an incident."