[Q] stock; reboot/restart loop? problem all of a sudden (GT-i9250)

[apoc [t.i.m.]]

I have a stock Nexus and now somehow overnight i've got this weird reboot/restart problem all of a sudden, my phone won't stop rebooting

I did absolutely nothing to or with it, i've got pictures on my phone that i really like to save first so that's why i didn't try a factory reset yet.
My question is how can I save/copy/backup my pictures from my stock Samsung Galaxy Nexus GT-i9250 (android 4.3).

I'm a some kind of a noob, so I was hoping for a "simple" some kind of 'for dummies solution' ???
I do have some computer skills, so if I know what to do I will most likely (probably?) succeed.

Thanks in advance and I hope I explained my problem clear enough?

With kind regards,
Tim