Abstract: A replacement sleeve for a heat insulative thumb tab that fits over a lever on a heated tool such as a hair curling iron. The replacement sleeve is preferably constructed of three parts: a base layer, a patch layer, and an insert layer. The base layer is an elongate strip of material, preferably made from leather. The patch layer is preferably made from a soft leather, such as suede. The insert layer is preferably made of a resilient type of material, such as cotton. The elongate strip of material is folded about a transverse fold line which separates the base layer into an upper portion and a lower portion. The lower portion is secured to one side of the upper portion to define a channel therebetween. Secured to the opposite side of the base layer upper portion are the intermediate layer and the upper layer. The assembled sleeve is sized and configured for insertion of a curling iron lever into the channel, such that all three layers provide the user with protection against heat retained by the lever.