"Smith isn't sick, sir," Captain van Tromp said to the peace minister, "but he isn't well, either.  He has never before been in a one-gravity field.  He now weighs more than two and one half times what he is used to and his muscles aren't up to it.  He's not used to Earth - normal air pressure.  He's not used to anything and the strain is likely to be too much for him.  Hell's bells, gentlemen, I'm dog tired myself just from being at one-gee again - and I was born on this planet."