Ixe2x80x99m using a MPB 15 Mid 2013 (the first retina MacBook). It has a Core i7 CPU (xe2x80x9dIvy Bridgexe2x80x9c) with a maximum specified temperature of 105 xc2xb0C. When using it, itxe2x80x99s mostly running at temperature levels of 90 to 100 degrees. There never was any hardware issue and it still performs perfectly. In other words, this is normal.
A late 2011 MacBook Pro also has a Core i7 (xe2x80x9dSandy Bridgexe2x80x9c) CPU. Itxe2x80x99s maximum allowable temperature is 100 xc2xb0C which means that 80 degrees is more than acceptable. From the processorxe2x80x99s point of view this would almost be xe2x80x9dcoolxe2x80x9c...
Apple has gone to great lengths implementing proper power and cooling management. Ixe2x80x99d therefore strongly recommend you refrained from using any of those third-party tools which fiddle around with temperature management. I spent 15 years of educating prospective Apple Service Technicians the proper techniques of servicing Mac desktops and portables. And I cannot remember a single incident of a Mac dying from overtemperature.
The only temperature level you should really be aware of is that of your hard disk (provided you donxe2x80x99t have a SSD built in). This is probably the only component in your Mac which would seriously suffer from extended periods of high temperature. But this topic has enough potential for a separate AskDifferent question.