My iPhone 4 gets hot as the battery is charged. To compound the issue, I think I bought a cheap case that traps heat, which in turns make the phone even hotter-- you can feel the heat by putting it in your hand when charging. However, once you no longer charge it, then the heat will go away.

My question is, will this damage the hardware? Also, to reduce the heat, I put the phone on the floor ( which is cooler) and I found that the device was not as hot as before ( previously I put the phone on a wooden table when charging). I am not sure whether my measure helps in elongating the battery life and protecting the electronics components?