On average, a good quality product will last you more than ten years. While this is a general thumb rule, if you want to know exactly when to replace your product, you should look for the warning signs. Look for the formation of any lumps or sagging in the product. You will know when it gets noticeably bad if you are regularly waking up sore. Another sign of an ailing mattress is that you will find it easier to fall asleep if you are sleeping on a different mattress. Unless there is any problem with your air conditioning, the problem might be with your bed.