Linux laptop CPU temperature (overheating) & fan speed

Question

Testing on two older laptops:

• Compaq Presario A900 with Ubuntu 10.04 (2.6.32-24 kernel)
• Gateway ML6720 with Fedora 13

both freshly updated, I noticed both of them have the same problem:

• Nothing in /proc/acpi/fan
• In the only thermal zone, ls /proc/acpi/thermal_zone/TZ01 gives:

cooling_mode polling_frequency state temperature trip_points

• cat /proc/acpi/thermal_zone/TZ01/* gives:

<setting not supported>
<polling disabled>
state:                   ok
temperature:             55 C
critical (S5):           100 C

or such under normal load (i.e. temperature is ~45-55*C under normal load, such as when browsing Web like now).

Obviously, there's no ACPI support for fan control. sensors gives this:

acpitz-virtual-0
Adapter: Virtual device
temp1:       +55.0°C  (crit = +100.0°C)                  

coretemp-isa-0000
Adapter: ISA adapter
Core 0:      +49.0°C  (high = +100.0°C, crit = +100.0°C)  

coretemp-isa-0001
Adapter: ISA adapter
Core 1:      +50.0°C  (high = +100.0°C, crit = +100.0°C)  

If you have or had any of the above models, did you have CPU overheating issues? For example, I can easily make CPU temperatures up to 85-90*C in a minute or two of hard work. This all with a fan underneath and another that helps the poor CPU fan.

I am also confused:

• Windows Vista doesn't have any issues like this. E.g. Flight Simulator brings it to ~65-70*C
• If there's no ACPI, I assume motherboard is controlling the CPU fan speed according to the current temperature. What's it doing letting it go to 80-90*C?

What temperatures are you experiencing during normal and hard CPU-bound tasks? I highly doubt it, but I have to check - maybe this is normal...

Lastly, I'm surprised I'm seeing this on much newer laptops (e.g. http://ubuntuforums.org/showthread.php?t=1327623) or even a mix of them (see e.g. bugs.launchpad.net/ubuntu/+source/linux/+bug/370173). Just wondering how people use Linux if so many people have issues on laptops...