Introduced in the late 1960s as a faster way to fix supper, microwave ovens use a special frequency of radio waves – called microwaves – that causes the atoms in liquids and fats to vibrate. That vibration creates heat and cooks food much faster than a conventional oven.
Microwave ovens cook food by generating intermolecular friction between the molecules of the food. The microwaves cause water molecules to vibrate; the increased friction between the molecules results in heat. Microwaves could affect your tissue in a similar way if they were able to escape from the microwave oven. Modern microwave ovens are designed to allow essentially no leakage of microwaves, however. The only time for concern would be if the door is broken or damaged, in which case the oven should not be used.
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