A:AnswerYes, I believe an extended period of over 100 degrees in a garage would be too much for this freezer. You should contact the manufacturer for conformation.
A:AnswerThis depends. Are we talking about the freezer not being plugged in? These freezers are essentially well-insulated coolers. Metal lining with foam sprayed inside every inch of the frame. If you are using it at a Farmer's Market for 5 hours with no electricity, I would highly recommend putting dry ice in it. The dry ice will stay cold for hours and will keep the freezer cold as well. Everytime you open and close the lid it should start to make what new air that got trapped in there cold again.
But to answer your question, the freezer outside even in the sun would still keep ice cream cold. But you got to make sure it's plugged in or the cold is being pumped from another source (i.e. dry ice).
Hope that helps.
