We have long been looking to replace our store bought water bottles with more Eco friendly ones.....there have been some commercials on TV for the Eco canteen...stainless steel bottle. My wife and I were talking about it and a question came up. Stainless steel vs the Nalgeen of the 'same' size. Forgetting the discussion of things like....you can use the stainless steel one to boil water....

Our question is....given all other things equal......which would remain colder longer......?