Which model do you have? Got Applecare?
2.4 ghz core 2 santarosa, Its 4 years old so no care gona happen here.
Apple would just say its operating with in safe limits which is true, I just remember how cool an quiet it was unless under heavy load when new. Its always over 40 c and regularly idle's at over 50 c.
On a warm day sometimes I dont want to use it because I know it will break me into a sweat, as I am coming to believe that all laptops do this in the end I want to find out what the cause is so I can either fix it or just accept this and arrange to just up grade regularly. I hate the idea of just buying a new machine every year like a good little consumer as Im quite attached to my macbook, Ive thrashed it everyday for over 4 years and its never let me down, anyone who says they are over priced doesnt understand what 'value' means IMO.
Tho I am about to buy a new one the problem still needs an answer as I bet money that after a year it will show signs of the same thing.
Seems to me it can only be one or a combination of the following:
1. accumulation of dust
2. reduction of TIM compound efficiency over time and use
3. greater load on the cpu from more programs running
4. slow degradation of the connections throughout the board over time and use
5. Fan getting louder as a result of wear
Seems to me there can be no other explanation.
Or, the temperature sensor is now wonky?