I have found when in severe pain to buy ThermaCare products. I use the lg/Xlg back warmer for back, neck, fingers (I wrap my hands in them), etc. There's one for knees! The neck one doesn't seem to give off enough heat. It makes a car trip bearable, the nighttime manageable, and daytime I can somewhat keep up with my kids. Well worth the cost. I buy in bulk at SAM's.