Ethernet shield chip very hot.

So my question is, is it normal that Ethernet shield W5100 chip is so hot that I can't even touch it for a few seconds? My Arduino will be powered on all days, so I am worried that ethernet shield life time will shortened because of overheating.
When I used 12V adapter for power supplay it smelled like something is burning (and it wasn't a bacon from the kitchen :D). So now I am using 5.1V 700mA phone adapter connected to the usb and its much better but I think is still a little too hot.
I am thinking to put a cooler on that chip. What do you think?

They do run hot. I have several that have been running for months. At least one over a year.

My ENC chip runs so hot that stops responding :frowning: I installed a ram heatsink and problems were solved, but it is a constant waste of energy (specially if you use batteries)