Your laptop is exhibiting a problem that is very common with the
Presario 2700 Evo N180 laptop family. Basically, the heat sink
module has lost contact with the CPU, so it has become ineffective
(hence, the fan blows a lot, and the laptop will shut off if you run
an application with a high CPU load for any period of time). Other
symptoms of this problem are the laptop running suddenly gets very
sluggish; using Windows Task Manager (found by right-clicking on the
task bar), under the Processes tab, a "system" process
takes up 100% of the CPU time. This at first may seem to be a
software problem, but it is entirely due to the problem I described
above.

The cause for this problem is a mechanical defect on the motherboard.
The heatsink module is held in contact with the CPU using four screws
that connect to four standoffs on the top-side of the Motherboard.
These four standoffs are connected to the motherboard using solder,
and the adhesion force weakens over time due to a phenomenon known as
metal creep. What happens is that the four standoffs come loose, so
the heat sink module has nothing to hold it down.

Happily, this is a problem that you can correct yourself. There is a
repair kit for this problem for sale on eBay. Enter the words
"Presario 2700 repair kit" and you will find a more
detailed diagnosis and a repair kit that includes the parts you need
to do the repair using only a screwdriver (no soldering required).
The kit also contains detailed pictorial instructions that show every
step of the repair.