Those aren't too high. That's actually average for most devices. Using 4G, browsing, having brightness up all the way, having GPS or BT on, etc will cause heat. Also the fact that its a 3000mAh battery, which will cause a lot of heat since there's nit much room to dissipate the heat.
So its normal. Anything constantly over 125°F and then I would say its overheating.
Yeah having the screen brightness all the way up really makes the phone heat up, I keep mine at 11% and only notice heat when under heavy load. I was uploading a 100mb files to Dropbox over 4G and it got pretty hot but that is to be expected, same for tethering.
Yep as they get smaller and thinner and screens and batteries get larger, there will be more heat issues. Most processors can handle temps up to ~160°F.
I concur with the above posts. Most importantly, the phone has built-in temperature monitoring and also has the ability to back off on processor speed, shut down unnecessary processes, and even if necessary do a soft reboot to prevent damage. Unless you see a warning on the screen about high temperatures, I wouldn't be too alarmed.
Also as Droid-Xer indicated in two posts above, there is almost NO EMPTY SPACE inside these marvels of technological miniaturization and compactness. This does succeed in giving us a phone that is "RAZR THIN", but it also means any component that generates heat has to transfer that heat directly to the outside of the phone via thermal conductivity, rather than dissipating it internally into air first, and then gradually radiating it out of the phone through Infrared Radiation or via airflow through openings in the casing. Furthermore, as we all want a phone that is "water resistant", this means there are virtually no openings from inside to outside large enough to allow airflow.
Anything you can do to reduce power consumption will also reduce heat generation since moving electrons generate heat, and the more electrons that are moving and the faster they are moving, and the more resistance the components put up against the electrons moving (think bright screen, Bluetooth, WIFI, 3G, 4G, GPS, Widgets, background email, Facebook, etc.), the more heat will be generated. The built-in Task Manager can do a good job of minimizing this by shutting down unnecessary operations when the screen is off, and of course since you can always start any applications again it will both conserve battery power and reduce heat generation.
Good luck! :biggrin:
biggrin