If you are making a recipe that uses raw eggs, you may in some circumstances wish to pasteurize them.
This can easily be done in a double boiler (or something you rig up to act as a double boiler). Simply place an egg in water in the top of the double boiler or inner bowl, and heat until the water temperature is between 135–140°F for 3–5 minutes. You may have to remove the double boiler from the heat source, and perhaps even remove the top pan or inner bowl, so the temperature doesn't rise too far above 140°F, which would cook the egg.
*Some sources seem to say that this method only pasteurizes the outside of the egg and not the inside, while others seem to say this method safely pasteurizes the whole egg. Use your best judgment. From my personal experience our mayonnaise lasted much longer in the refrigerator when made with eggs prepared in this manner, and since this method gets the eggs hot enough you have to be careful not to actually cook them, it would seem safe to be. However, if you are truly in a high risk group you may just want to buy professionally pasteurized eggs.