mu 4 s doesn't charge any longer and the battery overheat when I try to charge.

HI my 4 S doesn't take the charge any longer, and sometimes when I turn it off and plug it, it takes a little bit of charge but doesn't hold it long, and the phone get super hot. What should I do to fix that problem, I have donwload all the last version and the phone is only a few months old.

Thank you. Benj971