The shaking he noticed but didn't particularly care about at the moment because there were more important things to care about. They needed to head off hydra and figure out they were up to in the middle of no where. What they stole seemed so insignificant too and they just needed to slide back to the base as soon as possible. It had to be apart of a greater plan, especially considering Tony claimed he took care of it. Couldn't the man understand nothing else mattered?

Breathing out slowly, Steve looked off into the distance. "It's just cold," he eventually offered, fully aware the cold shouldn't impact him as much. The serum always kept him really warm. "What would you even do? We don't know what they did." To him, to whatever they were after. "We can't just stay here, Tony."