In the Experienced rules, it says that a firefighter that is Knocked Down (by fire advancing to their location) is placed on the nearest ambulance parking spot. It also says that they must "visit the ambulance to recover".
Is this just adding the "story" behind why they end up in that spot? Or is it meant to be literal, that they cannot take other actions until they (or someone else) radio the ambulance to that location? We decided to take it literally, since it seemed to add a bit more "cost" to being knocked down (otherwise it can actually be advantageous at times), but I couldn't find anything concrete one way or the other.