apple iphone 4 faulty !

for sale is a faulty apple iphone 4, i brought it of a guy with the intention to try fix it. After playing about for a while i did get it to power up but it said it cant use until cooled down or something along thoose lines. the battery in it is now flat and it wont charge. sold for parts/spares, has a orange case fitted front & nack and the back casing is cracked/damaged. hopefully someone will be able to make use of it.