Tempering eggs is the process of preventing eggs from clotting or cooking when placed into to too high a temperature.
To temper an egg you need a bowl and a whisk. Whisk the egg or eggs briefly in the bowl. Working with a few teaspoons or tablespoons at a time, add the hot mixture to the egg or eggs, whisking continuously. Once you have gone through this process, you are safe to add the egg to the bowl or pot of whatever you are cooking.