Sticking one's hand into an operating microwave oven is extremely dangerous and should never be done under any circumstances. Microwaves emit electromagnetic radiation, specifically microwaves, which are designed to heat food and beverages. These microwaves are absorbed by water, fats, and sugars present in the food, causing them to vibrate and generate heat, thus heating the food.
If someone were to put their hand inside a running microwave, the microwaves would penetrate their skin and interact with the water molecules in their tissues, leading to rapid heating. This can result in severe burns, tissue damage, and other injuries. Additionally, microwaves can also cause thermal injuries to the eyes and potentially damage internal organs.
Furthermore, the fact that your microwave sometimes fails to stop could indicate a malfunction or a safety issue. It's crucial to address this problem immediately and have the microwave repaired or replaced to ensure the safety of everyone using it.
It's important to educate your coworkers about the risks associated with microwaves and the proper usage guidelines. Emphasize that they should never attempt to stick their hands or any objects into a running microwave and encourage them to exercise caution and follow safety instructions at all times.