Also, the entire time I was reading this chapter, I couldn't help but think about how Case's collar would absorb ALL of the sweat. I cannot imagine it being pleasant.
Trained athletes don't actually sweat all that much if they don't specifically push themselves. Plus, their sweat is almost entirely water, so even if the collar would absorb it, it wouldn't be much different from regular frost - unpleasant to touch, but that's what the clothes are for.
I like how it was pretty cute and all, but now all we remember is that cliffhanger
That's because the meaning of each statement in the middle part is more or less clear, why the last sentence has not been clarified and thus can mean anything, increasing its relative semiotic weight.