CPU Fan turning on (laptop)

[Mathieu Malaterre <mathieu.malaterre@gmail.com>]

Dear all,

 I recently bought a new laptop (Toshiba L670). When using it for a
little while the CPU Fan is turning ON for no reason (IMHO). How do I
display temperature information on a latop ?
  I tried sensors-detect but it simply returned: "No sensors found!"

Thanks
-- 
Mathieu