Question

Ice boxes are often made as double walled containers. Why?

Answer 1

Answer:

Ice box is a double walled box generally made from iron The space in between walls is filled with glass-wool which is a bad conductor of heat Thus the heat from outside does not reach the ice and hence it does not melt for long time.

Answer 2

Explanation:

Because the space between the walls mainly covered with bad conductors of heat materials so as to prevent melting of ice by conduction or convection. OR

there is a vacuum in between these walls which also prevent melting of ice for long time by not allowing the heat to enter.