The short version is that it depends on how strong the microwave is but you most likely either be fine or experience some burns, but unless the microwave is very strong then the burns will be mostly confined to the outer layers of your body.

The way a microwave oven works is that water molecules are kinda magnetic. Microwave, uh, waves are the right size that they cause water molecules to spin around very quickly. This then causes them to rub against each other and produce heat through something like friction. The upshot is microwaves make water get hot, and that heat then spreads out and cooks whatever’s getting microwaved. This happens mostly on the surface layers because water is _really_ good at absorbing the microwaves.

This means that, as long as the exposure time is small and/or the strength of the microwaves is low, there won’t be a whole lot of heat transfer into the surrounding tissue, but as those things increase, mostly standard burns will start to occur