Why do heated tomatoes stay hot for so long?

Well, the water in a soup broth, for example, is moving around a lot, and when it passes close to the air or touches the bowl, it loses heat. but the water in the tomato is mostly trapped - it doesn't swirl around with the rest of the broth when you scoop up a spoonful. So the water in the tomato doesn't come close to the air or the bowl as much and doesn't cool down as quickly.