what fan?

ok - so I've had the PB for a couple of weeks now. I have not yet used to PB for anything besides email/web browsing - - so, I wondered if I SHOULD be hearing that fan that I have read so much about.

I bought the 'Podium Coolpad' and have used it all the time - and so, I thought that could be why I have NOT YET HEARD ANY FANS WHATSOEVER.

The bottom of the PB is certainly HOT - - and so, I read the posts here and downloaded Temperature Sensor from Versiontracker - here's what I got (after restart)
Processor/Controller Bottom - 55.5C
Processor Bottom - 52.8C
Power Supply Bottom - 51.2C
Trackpad - 40.5C
Battery temp. - 34.0C

Should I be worrried about NOT hearing any fan on my PB - - ever?

Thanks for any and all help,

Leigh-Ann