If Garrus swept through this area earlier looking for people, it would explain why Steve hasn't stumbled on anyone who might need help. Which probably means that they can head back for shelter themselves, with their eyes peeled for any stragglers along the way.

Usually Garrus is a lot more covered than this, so it's the first time that Steve's gotten a good look at the plating and scales that are not on his face. It does look like armor, honestly, and he has to wonder if there's something about the sand against it that feels... good?

Why else would Garrus have done that?

"To say the least, yeah. When sand is blown around this fiercely, it's enough to cause a rash on our skin, if not worse." Humans are pretty vulnerable in that way, although Steve himself could withstand a lot more. "Anyway, I... didn't mean to interrupt anything."

Does Garrus want him to leave so he can continue whatever it is he was doing...