[Q] Cannot delete anything or add to internal storage.

The phone was left out in the sun for an hour or so. Once it was brought inside the phone was off and would not turn on. I had to hold the power button down for about 15 seconds before it rebooted and turned on. The phone seemed to be fine for a few days. Then we noticed it would keep rebooting randomly, or so we thought it was random. Turns out the internal storage is inaccessible. You cannot add or delete anything from the phone. If you try, the phone will reboot. If you deleted something (an account, a picture, icon from home scree, etc) it will return after the reboot. I have went to recovery and attempted a system restore but all that happens is the screen goes black with a red triangle. When you force it to reboot everything is the way it was before. I have tried to access it via astro file manager and through win 7 and win 8. No matter which way you try you cannot delete or add to storage.

Any ideas or is it a brick?

Thanks for any advice or replies.

mbanken