K F:

It depends on what kind of arthritis you have..Be more specific. I may be able to answer some, due to my own experience with my back.

imsety:

Cold reduces inflammation and puffiness and relieves pain better than (though alternating between cold and heat provides greater relief for some people). But cold may increase joint stiffness. Heat relaxes muscles and tendons and promotes passage, so it’s the best choice for boosting the mobility of stiff joints. Finally, heat and cold can each help tame muscle spasms.
Whichever approach you choose, follow these precautions:
Apply heat or cold for only 15 to 20 minutes at a time, letting the skin return to normal temperature before reapplying.
Place a cloth or towel between your skin and the heating or cooling device.
Stop immediately if your skin blisters or turns any dark red or spotty red and white.
Don’t use heat or cold on hurt skin. And don’t use them at all if you suffer from poor passage, nerve hurt, or a shape up that may cause any of those problems, such as diabetes, Raynaud’s disease, or vasculitis. Hope this helps and excellent luck.