On the Apex ski patrol, we carry nylon slings to make a waist belt and everytime we ride the chair, we pick up a bag of rope at the bottom station. If they call a lift evac, we can rig up and tie a munter hitch on our carabiner and rapell off the chair to help in getting guests off as fast as possible. We practice it every year, but I have never had to evac during open hours.
At Beaver Valley in Ontario, they send up bags of blankets to all the riders of the chair while others are evacuating guests.