I am completely tired of my phone. Please help me. Please.?

My phone is so stupid, omg. Anyways, I have to wind up putting it in the freezer more than twice a day because the battery doesn't work when it gets hot. But no one else in the entire house has to! So, if someone could please help me, I would appreciate it. I need to know a figure of money. I need to know what it would cost without an upgrade (verizon by the way) to get a 32 GB Black Iphone 4 with unlimited text and calling. I want to know what it would cost overall once I got it, and the cost per month because of all of the charges. Please help me. I am in dire need of a new cellular device right now.