[Closed] badly bruised toe treatments?

gave my little toe a right whack during karate sparring last night, as a result it is pretty black on its inside edge.

Dont think it is broken as it wiggles with a little bit of pain and I can walk. It does hurt/throb a bit though and have a belt grading on Saturday.

So Ive heard you can do the cold water/hot water thing, or am I best to leave it alone, or god forbid put some "arnica" on it!! ....dont want to start that thread up again...!

Not 100% it isnt broken, but not sure how you can tell?