A great story from the memoirs of William Moore, an electrical engineer who worked on the Apollo program and had to venture out to fix a last minute problem with the Saturn V launch rocket while it sat on the launchpad or else face a mission scrub:
The Saturn V was more noisy and ghostly than I had ever expected and it had grown much taller and certainly more threatening since last week. The venting fuel made loud hissing sounds when relief valves popped or opened up suddenly. It was very easy to let your imagination infect your brain. This is a very dangerous place and everything seems to be moving in the heavy foggy mist. There was no way to talk to each other, heck, we could barely see each other and…we hadn’t thought of this problem so we held onto each others yellow protective clothing like kindergartners crossing the street. We all wore safety helmets but they just did not make you feel like you were really safe.