Q: phone dies

Hello pal4935,

When troubleshooting temperature, please refer to the following article:

iPhone, iPad, and iPod touch (4th generation): Keeping device within acceptable operating temperatures

http://support.apple.com/kb/HT2101

When using the device or charging the battery, it is normal for it to get warm. The exterior of the device functions as a cooling surface that transfers heat from inside the device to the cooler air outside.

By all means, if you believe you may have an issue with your battery, it may be best to read over the relevant infomration in this article:

iPhone: Hardware troubleshooting

http://support.apple.com/kb/TS2802

Thanks,

Matt M.