I need to make a thermos with natural materialsI can't use Styrofoam and the only materials I have are pieces of cardboard, aluminum foil, cotton balls, and Popsicle sticksI also have no artistic ability.
Use the aluminum foil as your interior liner to hold fluid and the popsicle sticks as the structureSurround this with cotton balls and finally wrap it in cardboard as your outer linerThe key is to insulate your interior liner (aluminum foil) like a coat would a person to reduce thermal transfer to the surrounding environment.
