Whisk constantly by hand until mixture is warm to the touch and sugar has dissolved. (banglarecipe.net)
Place the bowl over a pot of boiling water and stir until the sugar has dissolved and the egg whites are warm to the touch, about 2 - 3 minutes. (pastryaffair.com)
Apply the already prepared cinnamon roll icing when rolls are warm to the touch. (nielsenmassey.com)