It's not always true that the plate doesn't get hot. In the case where it says cool it is because the materials that make up the plate are not very microwave absorptive. For example, glass is very microwave transparent and so won't get hot.That may be true for other dishes as well. However, one has to be careful with china, especially that manufactured in China. There are two types of china dinnerware - glazed and unglazed. The glaze on china has to be formulated with materials that do not absorb microwaves and heat. Lately, we have found that much of the dinnerware coming from China has glaze that can become very hot - up to 300 F. As to unglazed, it may absorb water and it is this water that becomes hot. To determine if you dish heats or stays cool, put an empty plate in the center of the microwave oven with a cup of cold water in a corner and then turn on the microwave for one minute and see if the plate remains cold or gets hot.