Instruct: Classify Amazon reviews into positive or negative sentiment
Query: ONLY STAYS COLD FOR 10 MIN. CANNOT BE RETURNED

These ice packs only stay cold for 10 minutes! That is obviously not enough time to offer any kind of therapy or medical aid. The worse part is that Amazon will not allow me to return due to a 'hazardous material' policy: "For safety reasons, items that are classified as hazardous materials or use flammable liquids or gases cannot be returned to Amazon.com." This seems bogus because they sent this 'hazardous material' to me! DO NOT BUY! DO NOT WASTE YOUR MONEY