Bobsled
Runners (the blades under the sled) have to be a certain degree. If they are not within 4 degrees of it then they are disqualified for being too hot or too cold.
Luge
Men have to be a minimum of 198 lbs, 165 lbs for women to participate in the luge. If you are too light then you are allowed to strap weights to yourself to hit these minimum targets.
Skelton
You have to cross the finish line ontop of your sled but you can get off of it and push it or move it on the way down.