Re-heating and tweaking the shape is a real benefit of the Zapz footbeds because when you transfer them between your favorite footwear you may find some little inconsistencies that can be worked out by re-heating. However, Hal warns that too much reheating can possibly delaminate the non-gel parts of the insole which is another reason to have the Zapz installed by a professional.
Since you can (in a pinch)do them yourself I recommend you might want to take any extra pair with you when you travel to ski, then Heaven forbid – the airline misplaced your ski boots - the Zapz Microwavable Custom Insoles can be a quickly adapted for an affordable ski boot footbed.