Flashing red screen to apple logo- Help, daughter freaking out!

Hope someone can help me with this before my daughter has a total breakdown. She has an IPhone 5S. Nothing has happened to the phone negative in anyway- no drops, no water, etc. She came and said it just started going back and forth from the Apple logo screen to a flashing bright red screen. The logo screen stays up for approximately 5-6 seconds then flash over to the red screen. Back and forth. I have tried the holding og Home and Sleep button. Phone does turn off but same thing keeps happening. Tried to reset in ITunes but neither the computer or ITunes are recognizing the IPhone. Please help!