What Causes Burning Sensation And Pain In Knee?

Hi Doctor, For the past 30 days I feel a burning sensation and light pain in my left leg portion above the knee. If I apply some pain reducing solution i am getting some relief but not fully. Before 30 days, I went to Paris Disney where the climate was very cold and I stayed there for 3 days. After that only this problem cropped up and before that there was no pain in my leg