What a washing machine does to a thermal bag depends on the inner layers more than the outer fabric. The drum can crease and crack a foam insulation panel, bend a rigid base and push water through the seams into the insulation, so a bag that is dry outside stays damp inside. The decision takes four steps.
- Take out the base board, dividers, strap and ice packs. If the rigid base cannot be removed, the bag stays out of the machine.
- Feel the insulation. A rigid foam panel or a foil liner can crack where it folds; with insulation like that, the bag is cleaned by hand.
- Read the label: the number in the tub is the maximum water temperature, a bar under it calls for a gentle cycle, a hand in the tub allows hand washing only, and a crossed-out tub means no washing at all.
- Dry the bag with the zip open and its shape supported. If moisture or odour remains in a seam, keep it out of dispatch.
