Any aid given to a racer will disqualify the racer for that run. This means retrieving any equipment or clothing or helping in any way. If a racer appears to have injuries that may be aggravated by being moved, place yourself in a highly visible position on the course so the next racer will know to leave the course. Find an official with a radio. If need be, send a skier to the finish so help can be summoned.
Warm clothing including a good water-resistant jacket, warm hat, and gloves are usually the minimum.
A foam pad placed between you and the plastic bucket makes the bucket a more comfortable seat and a heck of a lot warmer. It's not too unusual to have the weather change dramatically during the day. The down side of liquids is the time you are required to remain at your station is always directly proportional to how bad you have to go and the distance to the restrooms.