How To Treat An Injured Ankle?

My friend recently twisted his ankle while playing tennis and his ankle became very swollen. He said it hurts but not so much that ii's broken. He can't rotate his ankle and now his foot is beginning to swell as well. Now, purple spots are beginning to form on his ankle and this grows a concern for us because there are no doctors available right now to check on it. Should we be worried? He's 17.