Most with an untrained sense of smell wouldn't notice, but there was a very distinct smell that came from t-cog strain, usually due to rapid transforming or transformation without safety protocols in check. It was hard to smell over the scent of flowering spores, but First Aid wasn't exactly unfamiliar with it. He's had plenty experience with t-cog issues, including his own.

His intent was to gather fresh, sporing samples of the flora blooming; he was infected already, so he didn't have much to lose. The smell puts him into immediate medic mode though, even as his systems scream for relief from charge. He picks up his medical bag and drives off, sirens blazing, to the source. As distracted as he is, he doesn't immediately recognize the dark purple frame until he's transformed and back on his feet.

It's when those blazing red optics behind that mask set on him that recognition sets in.

"I should leave you to die out here in the dust."