Actually, he has been required to portray such a situation many times during the filming of Star Trek. He describes it in an amusing way in his book, "Get A Life". I'll try and find the quote later...

Just imagine convulsing your features in a grotesque grimace, gasping, half-doubling over, bugging your eyes way out, clenching your jaws, and moving your arms in jerky motions like a frog that's being electrocuted. That sort of covers it...