Smoked hams are fully cooked hams that have been cooked through a variety of processes. Some smoked hams are naturally smoke-flavoured due to the cooking method (such as using a slow smoker with wood), while others are milder and have smoke flavouring added to them. Either way, they come from the store ready to eat right out of the package. If you do not want to eat your smoked ham cold, you can heat it; heating a smoked ham is very easy.
Preheat your oven to 162 degrees C.
Calculate your cooking time: multiply the weight of the ham (in pounds) by 10. That is how many minutes you need to safely heat the ham in the oven to a temperature of 60 degrees C.
Remove all packaging from the smoked ham. Failing to do so could cause melting or even a fire once placed in a hot oven.
Place the smoked ham in an oven-safe pan or dish and place in the oven.
Check the temperature of the ham after the calculated heating time has passed. Once the thermometer reads 60 degrees C, your smoked ham is warmed through and ready to eat.
If you need to heat the smoked ham in a hurry, you can raise the oven temperature higher than 325. Though it will cook faster, the potential for the ham to dry out is also greater. If you raise the cooking temperature, keep an eye on the ham so it does not go dry. If your smoked ham was pre-sliced, wrap the entire ham in foil before you place in the oven. This helps to keep the moisture in the ham so that it won't dry out.
If you bought your ham from a source that does not conduct USDA inspections, you should heat the ham to an internal temperature of 73.9 degrees C instead of 140. This is to ensure that possible food-borne bacteria are destroyed and the ham is safe to eat.