I would just make a counter, and every tick would add 1, and make a condition that if counter greater then a certain number, when player is on the floor, trigger once the damage stuff and reset counter.
Thanks megatronx.
I went with your idea and it seems to be working well. For anyone who may look at this thread, here are the steps I used:
[attachment=0:27dskqli][/attachment:27dskqli]
When falling from a large distance, the player will flash and loose 1 health.