Check out http://www.dippendots.com for more information here is a tid
bit from there home order form......

THE PROPER SERVING TEMPERATURE CANNOT BE MAINTAINED IF REMOVED FROM THE
CARTON AND PLACED IN YOUR HOME FREEZER. YOUR ICE CREAM WILL REMAIN
FROZEN AS LONG AS: a) there is adequate dry ice inside the box
(approximately 24 hours after arrival), b) dry ice is kept on top of
the ice cream and, c) the container is kept in an environment of 70°F
or below. Dry ice will dissipate when exposed to air. For your safety
do not remove dry ice from shipping bag.