That's a good sign Ahmed, and one I had forgotten to mention. Although, in the grand scheme of things a few degrees is not that big of a deal, so I wouldn't worry about it.
I think your first order of business today would be to call them up, explain the overheating issue and request a replacement battery. They will in turn, attempt to connect you with tech support, who will then try to "troubleshoot"; the issue with you while you're on the phone.
Explain to them that it's a replacement phone and this obviously shouldn't be happening. You might also mention, that you shouldn't be required to run your device in "power saving" mode, in order to keep it from overheating.
Explain to them you've done everything to remedy the problem before contacting them. And when they ask what you've done, (and they usually ask) tell them you've gone into recovery and cleared cache, data, and performed a factory reset. (btw....you have done this right? If not, it's worth a shot, but I don't think it will clear up this particular issue)
Stress your concern regarding these high temps and that you don't want this excess heat to ruin your device 6 months down the road. As you did here, point out temperatures when running the apps you mentioned at the same time. Tell them you'd like to try a replacement battery first, in the hopes that swapping out the battery will solve your problem. If they go for it that's great. Try that out for a week and really work the phone hard by putting it through a series of "stress tests" if you will.
Don't forget to take a number of screen shots along the way to document your findings.
Good luck & keep us updated. :thumbup:
tap'n