iPhone frequently blocks and restarts
My iPhone5 (OS 8.1.3) relatively frequently will block — totally unresponsive — and then either I need to do a force restart or it restarts itself. This may be weekly or several times per week. Most frequently it seems to be in the morning when I have woken it up and is updating podcasts and applications.
What is going on? What to do?
Thank you in advance.
(Reposted to correct typing error in original.)
iPhone 5, iOS 8.1.3