iphone 5 blue screen of death

Today my newly purchased Iphone 5 (bought last week or so), had a blue screen of death. Slightly freaked out, I did a reset(?) (pressing the top lock button with the home button) until it restarted the phone. It was sucessful in doing so, and the phone worked fine.

Then within the next hour or so, out of nowhere again another blue screen occured. This time, instead of just a continuous screen of blue like previously, it flashed blue then went completely black. No amount of button pressing brought any kind of reaction, so I did a hard reset (held home button for 20seconds or so, until the apple symbol appeared).

The phone is working as normal again after the reset, but Im terrified that it will be a continuous occurence, especially seeing as this is my first iphone and newly purchased. The phone wasn't hooked up to a usb or anything, (cloud is activated and i was using wifi, but thats normal...), and I was simply listening to music and using a writing app (like a note pad basically). So I cannot understand why it suddenly showed the blue screen of death twice.

Any reasons as to why it happened, and if possible how to make sure it doesn't occur in the future?

Thank-you,

M.Jackson.

Edit: Okay, after the second time it worked, I connected it to the pc via usb, and now I have to restore to factory settings as it wasn't registering my iphone.

What is happening?!