Skeleton is held on one of the artificially refrigerated ice tracks around the world which vary in length from around 1200 to 1500m.
At the Olympics skeleton is a four run event, with the gold medal going to the competitor with the best aggregate time.
Runs are timed electronically to the nearest hundredth of a second.
Athletes can reach over 140Km/h
Only the prone position is allowed, although competitors who come off the sled temporarily, are not disqualified if they cross the finish line back on the sled.
There is a limit of 30 athletes in the men's event and 25 in the women's.
In the second run, only the top 20 from the first run can start. They start in reverse order of finishing time in the first run.
There are quotas for each nation taking part based on their World Ranking over the course of the International Competition Season
Athletes use specialist spikes called brush spikes to enable them to run and push their sled at the start to gain the quickest possible time. There are over 300 small spikes in each pair of shoes.