I recently got one today, I heated mine up at school in 3rd period for the first time, reached 130 degrees fahrenheit. I enjoyed it and boiled mine, it stayed hot for about 40 minutes this time vs the 1 1/2 hours before. Anyone else have these? I would give this a 7/10 (I had to buy it for $6 which is good but still expensive, the actual price for them is like $10)