"Bloodstream, brain and spinal cord. It's connected to my central nervous system so my suit reacts as fast as a brain impulse. I can connect to electronic devices through Extremis, things like databases...hospital equipment. I can shut them down or troubleshoot them that way." He didn't want to go into that much because it reminded him of when he'd taken Happy off life support through Extremis so Pepper didn't have to turn it off herself.