Despite the title, I am trying to keep this serious (and at least G-PG13) as I've been wondering about this. It's been quite hot here, and given what Claude's usual outfit (as far as we know) is, I was wondering what he'd wear when it got hot. His "regular" outfit in its entirety would likely cause him to get heat stroke. As amusing as the idea of him with nothing on is, I think at the very least Claude must wear shoes to protect his feet, and some type of light pants or shorts with pockets not only for protection but also because we all know how he tends to nick things (gotta put them somewhere). He'd probably have a shirt on too. I don't know if his gift affords him any UV protection. Claude still gives off heat and it's likely he can feel it too, though I don't know how much affect UV rays have on him and there are some things you don't want sunburned ever. Also, NYC is crowded and if people can't see Claude, they are likely to bump into him. There are parts of the anatomy you don't want accidentaly bumped either. So in all seriousness I imagine Claude might look like this in the summer:
That's not a manip. That's a cropped shot of Christopher Eccleston, courtesy of the fantastic Smug Mug, from a TV appearance when Chris visited Banda Aceh after the tsunami (article here). Of course there's always the possibility that Claude just hides his coat (and hoodie) somewhere:
That's a cap I did off You Tube from the behind the scenes "Distractions" clip, sorry about the quality.