Back UPS Pro 500 - How hot should the case be?

[raynerph_apc]

Hi,  I have a Back UPS Pro 550 and I've noticed that in one location the case is feeling hot to the touch.  It's hot enough for me to have become concerned about it, but it's not not yet hot enough for anything like melting, charring, etc to take place.  The unit shows no warning messages.

To described the location, when looking at the UPS from the front (i.e. looking at the LCD display), on the left hand side of the UPS the hot spot is approximately 16.5cm up from the surface it is sitting on and 12.5cm from the front of the LCD display.

Do they all get hot in this location, is this normal?

Thanks