All trains and stations are designed so that you can get run over without damage, either between the tracks or in under the platform were there is always some space. Just make sure to not keep any body part on the tracks, and don't touch the third rail, often on the far away side from the platform in most metro systems, overhead wires are safer, but you should be careful there too as there's a risk of electrocution there too.
It's nasty down there and not very comfortable, but fully survivable for a few minutes while they check to see that you are still alive and slowly move the train.
It's nasty down there and not very comfortable, but fully survivable for a few minutes while they check to see that you are still alive and slowly move the train.