Replying to Canon Help

Hey guys, I recently came across a pretty big problem, and need some help to figure it out.

I was taking some photos on my t3i about a week ago with a fully charged battery. Expecting everything to be working fine, I took my whole kit with me up to Big Sky, only to find out that it wouldn't turn on.

Both my main and backup batteries are fully charged, and the battery door is closed.

Can anybody give me some words of advice?

Any help is greatly appreciated and karma will be awarded.

Thanks!