bump to the head

[ColeAreeaJet]

Does anyone know how long you are supposed to wait after getting a good bump in the head before you can safely fall asleep?

My 9 yr old son and his friend were throwing rocks in the puddles in the park and his friend threw a pretty big rock that hit my son in the forehead.  He had a small gash on his hairline, it bled a lot but it's superficial (no need for stitches).  He was upset for a while and really worked up.   It has stopped bleeding, we couldn't bandage it because it's in his hair, but he has calmed down so that's good. Now he's watching TV and starting to fall asleep.  It's been about an hour since it happened.  I know you're not supposed to fall asleep right away after a bump in the head in case it's a concussion...  just wondering if anyone knew the actual time limit.

[JulyBabies]

Not sure. Once spent an entire night in the ER because I didn't know. My daughter hit her head and we weren't sure what to do and didn't want to take any chances. She was just fine.