FYI I have the same mod in the normal nylon plastic (not the alumylon), and the F/A reading on mine is 43.17, so I'm guessing it's normal for these boxer DNA 200's. Anyway the readings on mine... Case cooling time constant: 506.61 s Case Heating Time Constant: 653.69 s Case USB charge Temperature Rise: 13.65 F 43.17 F/A Minimum Ambient Temperature: -20 F Maximum Ambient Temperature: 110 F