Firstly, I Thank You. My 19 Y/o Son Has Suddenly

Firstly, I thank you. My 19 y/o son has suddenly developed extreme pain in his lower right, rear hip region and knee. He is in excruciating pain. He is 6'3" and exercises regularly. This pain began last night and is not alleviated by ibuprofen. It is a holiday weekend and I am unable to contact any of my doctors. He is not a squeamish man, ergo I would greatly appreciate any advice. He does not feel going to the hospital would be beneficial, I conquer. I have Aspercream, Tiger Balm and a lot of love. What can I do?