I have two kids, and both of them have done that to me...my daughter more then once...and like your son, out of nowhere - and at night. Makes you wonder what sets it off. Usually it ends up being croup, but there is nothing worse then seeing your child gasping for air. I am glad he was alright after you "puffed" him. I don't have inhalers in the house. We have always ended up taking them outside wrapped in a blanket (if it happened in the winter), or into the bathroom with a hot shower running. The cold or steam usually helps out so we feel confident to take them to the hospital. It is scarry though! I am glad to hear he is alright!