A vitrification warming protocol is the validated procedure for safely removing cryoprotectants from a vitrified oocyte or embryo after storage. It involves exposing the vitrified sample to a series of warming solutions with decreasing cryoprotectant concentrations, buffered with sucrose to manage osmotic shift and prevent membrane rupture. The warming must be rapid enough to move the sample through the critical temperature range where devitrification (recrystallisation) could otherwise occur. The entire process typically takes 10 to 15 minutes and must be conducted on a temperature-controlled surface such as a heated microscope stage. Using a validated warming kit matched to your vitrification carrier and reagents is strongly recommended.