How long ago did machines have these? Are temp sensors on the mobo? IIRC... I had a program that was reading my temperature many moons ago on Win98SE. I have a five year old Hewlett-Packard model 8650C .534ghz Intel Celeron.

Can I get a reading of temperature for KDE or GNOME? Through widgets, maybe?

If you your HP is laptop, try omnibook project at sourceforge (there is also KDE applet)

if not, try lm_sensors

Really the temperature reading have been around for a long time. It simply reads the voltage drops on the mobo at certain co,ponents near the CPU and near the outer edge of the mobo. Like I said it has always been available, but the programming availablity to do it has been in the last decade. There are many programs online that can be used to do this and most are free dowloads. Granted there are many more for windows than for UNIX/LINUX, but they are out there. Best way to find what you like is the simplest, go to google and search it up, specify fr Linux and you should get 50 to 100 hits there. Good luck