My laptop works fine in Ubuntu but temperatures are higher than the rare cases I use Windows.
If there a way to tell Ubuntu to turn the fan on earlier?
I'm on Ubuntu 12.10 AMD64 on a Toshiba R830 laptop.
Fans are normally controlled by the hardware in response to temperature, so you don't need to worry about it -- if the system gets too warm, it will speed up the fans automatically.
You may be able to setup lm-sensors to detect the fan controller and the fancontrol
package to take over, but this is not easy nor a good idea. You would start with running sensors-detect
to see if it can detect any recognized chips and setup the driver for it.