What about a fan blowing over McIntosh 7205 AMP?

I don't see how it could harm it,but,it's better to set your fan up to pull heat from the unit.Just my opinion.

Warm is normal, why the need for a fan, is the amp going into thermal shutdown? Typically, fans are used to exhaust the heat from the enclosure thus creating a more natural cooling convection. I know that designers of tube equipment frown on fans blowing directly on the tubes as it could excite the tube thus causing microphonics and noise. I am not aware of any amp in which the fan blows onto the electronic, most exhaust the heat.

That could be a really good idea. Use the fan as an exhaust. pushing air away instead of right on it...thank you

Blowing air ONTO an amp may actually make it run warmer by inhibiting the convection of air from the top...sucking in cooler air from the bottom.
TPreaves is right....pull air out the top, rather than blow it in.
A small computer style box fan, on top aiding the natural airflow would help.
I have experimented with an old Intel CPU fan running off a 9v battery. Extremely quiet and moves a surprising amount of air.

That being said, the other posters here are right....and the amp is supposed to run warm. But not hot, depending on many factors, including class of operation and the amount of heatsink vs power. Lots of heatsink is needed for class 'a' amps while my 'd' amp has minimal heatsink, lots of RMS power, but a short time limit at those power levels.

Factors for any given amp, such as low sensitivity speakers run loudly in a larger room will (can) tax even the most robust amp making extra cooling or at least a well ventilated space a good idea.

Make sure your not blowing dust into it. The dust could clog things up, and is a known problem for some laptops like Toshiba, and others. I use muffin fans myself on warm running amps. When I had some inefficient 4 ohm speakers, I had to.