We've had it happen, too, with a 3 year old, and it was no problem. They definitely have waterproof pads on the beds, it did not go through to the mattress. We just called mousekeeping, let them know what had happened overnight, and it was changed during the normal housekeeping time. Maybe they changed it faster, but we were gone to the parks so who knows. I'm pretty sure this must happen at every resort at least once per night!