Every time I open a (php) project in Netbeans or PHPStorm, the CPU temperature goes up (I can hear the fan speed change, it starts running fast and hot air comes out) always reaching ~70°C, which as I suspected, is too much. At that point I kill the IDE and the temperature goes back to normal, ~30-40°C.
Apparently what causes this is that these projects have too many files, with lots of namespaces and cross-references, and the IDE tries to scan them all as fast as possible.
All this happens in my new i7 laptop. My old i3 desktop does not heat up with those IDE's.