An article of footwear comprises an upper portion which is dimensioned to at least partially enclose a user's foot, a sole portion connected to the upper portion and a solid microwaveable, insole shaped heating pad. The sole portion includes a pocket which is dimensioned for receipt of the heating pad. The article is adapted for removal and insertion of the heating pad by means an openable fastener which connects the upper portion from the sole portion. The invention also relates to a method of heating a foot comprising the step of providing an article of footwear according to the invention, removing the heating pad from the pocket of the article of footwear, heating the heating pad in a microwave for a suitable amount of time, inserting the heating pad into the pocket of the article of footwear and placing the article of footwear onto a users foot.