Might be a sign of infection

You would think but it’s only at night and not every night. It’s always associated with stiffness and extreme pain I have psoriatic arthritis and my hands and feet are also in horrible pain that I have not found a biologic to fix the problem yet and I’ve gone through six of them so far

Cold

Have to admit, it's not just my knees that get hot, my whole body starts to sweat every night.