It's always sad to see someone removed from Survivor for medical reasons, but Russell's removal was particularly harsh. As Jeff said, he was extremely well-positioned in the game. But the thing of it is, this was his own damn fault. His pride did him in. He was tired-- his tribemates saw that, and suggested that he sit out the challenge and rest. But he couldn't see just how bad off he was, he let his pride trump his prudence, and he paid the price.
I would love to see a season with everyone who's ever been removed for medical reasons invited back. There aren't enough of them to make up a full cast, so throw in everyone who's ever been voted out first. The season of second chances. People try so hard to get onto the show. Getting medically removed or voted out before the game's even really begun must be a tremendous blow. Give them all a shot at redemption.