Just got the heat pack today. When I got it the packaging around the product was open, not sure if it was previously opened or if it was just faulty packaging.But I've already heated it up twice and it works great! It puts out a lot of moist heat, the back of my t shirt is already damp from it.When I got up today I was having lots of back pain, from a car accident I was in back in 2010. It took about 2 minutes with this product on my back before the pain went away. This product is big enough to cover the entire back, so if your like me and don't know where the back pain will shift next, this is an excellent solution! I have not yet noticed any odor coming off of it, but if I do I'll be sure to comment on this post.Overall great product! I completely recommend it!