By STEPHEN TALL Illustrated by NEWMAN How warm should a handshake be? The answer may be more vital than you could guess! The three young men sat quietly and watched the faint eerie glow. It was ruddy and small, a spot of dull red color. For perhaps five or six minutes it showed, moving slowly along what seemed to be the lip of Bighorn Glacier, six miles away and seven thousand feet up in the thin cold air. Then it vanished. John Drinkard lowered his binoculars. "Well, that's that. You can see it