Instruct: Classify Amazon reviews into positive or negative sentiment
Query: If you want "cold" for more than 1/2 hour, don't buy it!

Consider this review from the standpoint of a biker...Even after placing in my freezer for about 1-2 hours before leaving on my ride,about a half hour out, all the ice cubes had melted. After another half hour the water was at room temp. Not good.Unlike some of the other comments, my bottles did not leak, and they were positively odor and taste free.After some research I came upon the Thermos products. The specs were just right! I received them yesterday (from Amazon)and "test drove" today. I filled both bottles with 6 ice cubes and water at 9:00am. I drank one bottle about an hour into my ride...it's now about3:50pm and the other bottle still has ice chunks, and very cold water.The Thermos product has a double stainless steel wall with vacuum. The Polar just can't compete.Amazon price for the Thermos is about $16. Well worth it in my opinion.