Inside a heat-safe bowl (you could use the pot of your stand mixer, if you own one), beat the whites together with the corn syrup, sugar and water for one minute until everything is combined. Make sure the inside of the bowl where you are mixing is totally dry before adding the ingredients.
Set up a double boiler. You will need a pot with boiling water on top of where you can put the heat-safe bowl you were using in step 2. This will help the sugar dissolve into the egg whites, heating them up without cooking them through.