frog on its back

I just got my first pdf, a powder blue tinc, today, and it was in it's tank for about 2 hours before I turned off the light. I went back a few minutes later to check on it, and found it on its back. I quickly went into its viv and and turned it over, it was still breathing but very nonresponsive to my handling it. I set it right side up inside of a cork tube laying on the substrate to maybe make it feel secure. My thermometer read a little over 70 f but only have the one thermometer so cannot verify its accuracy, my hygrometer read about 70%, the frog is a little over an inch long and unsexed. I just got the frog tonight so I have not yet fed it, the lights are two 6500k cfls. It is housed in an 18" cube. I am going to continue searching for the cause, but any insight would be very greatly appreciated.

Thank you,
Ryan T.