I Am 51 Years Old, And In A Very Good

I am 51 years old, and in a very good shape due to eating healthy and working out at the Jim. I had a total knees replacement both about 10 days ago! My recovery goes well and with good progress, even better than expected, however, since then, I'm facing waves of cold and hot, and when hot, and while sleeping, it accompanied with night sweat up to that all my cloths, my bad and pillow are wet. Is it something that is common after a major surgery like the one I had? Isaac