A55 heated up problem encountered

I have used A55 for 10 days, and shooting birds at sunrise with 500mm f8 reflex for two times so far.

Last Satuday after shooting birds (using 10 fps) for about 2,000 photos, when taking birds flighting, suddenly A55 lock-up and shown "too high temperature". So I have to cool it down for over 5 minutes before I can shoot again.

So A55 is not a heavy duty camera for spot / action shooting.