intel PIV 2.4GHz HT/D865GBF temperature enquiry!!

I'm using intel PIV 2.4GHz HT processor/D865GBF motherboard. I bought
it 6 months back.

Under normal working conditions(using explorer/MS word etc..) CPU
teperature is around 37 'C. but when I run Age of Empires/nfs/ Unreal
Tournament/nortan antivitus and other heavy softwares, the CPU
temperature shoots up to as high as 50 'C(extremely high for intel i
feel).

Is it normal?plz let me know if it is and if not what might be the
reason behind?

Thankx

I have intel active monitor installed on my comp!!today while playing
age of empires, it beeped and flashed the following alert:

02/01/04 15:15:35
The system temperature (Processor Zone) has returned to its
recommended temperature.

02/01/04 15:15:34
The system temperature (Processor Zone) has exceeded its recommended
maximum temperature.

such an alert has popped up for the first time!!now what?