Over heating core i3 330M in Acer Aspire 4740G

Hello,my Acer Aspire 4740G has Core i3 330M,4Gb DDR3 it shuts down all of a sudden and the laptop was very hot. is that an auto-shutdown feature?my temp never goes below 50*c on standby and when i open a program it goes up to 85*C.how can i keep the CPU from getting fried?i already have a cooler fan under the laptop.