Cpu running hot. is thermal paste needed on the heat sink?

[odyssa]

my CPU's run from 38 degrees to 42.... do heat sink needs some thermal paste?

 

[MockingbirdUK]

42 degrees is absolutely fine for any modern CPU, and is not a cause for concern.

There should be SOME thermal paste between CPU and heat sink, but if your max temp is 42 then your cooling is absolutely fine.