So, why 140°F? Well, it's all about killing bacteria and other microorganisms that can make you sick. When you heat ham to the right temperature, you're essentially giving those little critters a death sentence. It's like a heat wave for bacteria!
But here's the thing: not all hams are created equal. Some, like prosciutto or country hams, are dried or cured, which makes them less prone to bacterial growth. Others, like city hams or glazed hams, are more like wet sponges, just begging for bacteria to come and make themselves at home.