It should go without saying that having adequate Insurance is a neccessity for your Ski holiday!
You will often plan your trip well in advance, so being covered for cancellation due to unforseen circumstances is the first factor.
The most obvious part is being covered in the event of an accident on the slopes. Without insurance medical treatment abroad could be very costly, even a just broken wrist could cost £5000. Then there is the cost of sled recovery off the mountain, or even a helicopter trip to hospital to consider.
Bumping into someone else and facing an injury claim could mean financial ruin.
Shop araound for cover, there are many specialist Ski insurance companies or brokers, and cover may also be available through a finacial institution that you already deal with, like your bank or building society. Holiday insurance is often provided as part of a banking package, but be sure to check with them if you are covered for winter sports and if this insurance is adequate.
Multi Trip insurance can be a good deal as you can cover your summer holiday as well, but you may have to purchase add on cover for Winter Sports.
A lot of policies will not cover for off-
Some Insurers now make it mandatory for you to wear a helmet. Wear one anyway, but check your policy if you don't.