In the mid-1990s, I was visiting three of my client's offices, in London, Oslo and Frankfurt. No problems until my overnight in Oslo (after the client visit) - I came down with one of those 48-hour fevers that seemingly came out of nowhere. Thankfully I had a day off between Oslo and the client visit in Frankfurt, so I laid low at the hotel. I did buy a thermonether at a pharmacy, and discovered that my temperature was 103.2 F. Twenty-four hours later, it was completely gone, and I finished the trip and flew home in perfect health.
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As far as hangover stories, I'm not much of a drinker, so have none of my own. However, my co-worker had a good one. He and the project team flew from SFO to New York for a client meeting, checking into a Midtown East hotel the evening before the meeting. My co-worker, a native of NYC, decided to get together with some of his old high school buddies.
The next morning, he was a no-show at the team breakfast (last chance to go over issues before the client meeting). A team member left the breakfast to knock on his room door, to no response. In a panic, hotel security was summoned and, when the door was unlocked, there was my co-worker, drunk as a skunk and out to the world. The male members of the team got him up and into the shower, while a pot of coffee and a pitcher OJ were ordered from room service (he was essentially force-fed these liquids).
The most surprising thing was, he sobered up quite quickly, and the meeting ended up being quite successful.