If she's built anything like one of those life-sized dolls with silicone flesh, you'd think heating would be a huge issue. Think about how warm your PC's exhaust can get in a relatively open and thermally conductive enclosure.
Being buried deep in a very effective thermal insulator, it's not surprising her processor overheats when she has to frantically process new and unexpected situations.
Worse, that motor that runs her key tends to become active and spin during those situations, which would only add to the waste-heat issue.
She's bound to have some kind of advanced liquid cooling system, so it's probably not as bad as your standard PC. I would have to guess the radiator is in the top of her head based on this image.
Also, I love how Nakamura is the most stoic one here. Like she's conducting some kind of experiment.