Same thing I carry the rest of the time...
Shield in .45, sometimes with a Kel-Tec P32 on my ankle.
Unless I can carry OWB, in which case I've got a CZ-75 compact on my belt right now.
As the weather changes, I either sweat more or less. My clothing styles don't vary much, except that sometimes when it is really cold I'll wear light-duty ski pants over my normal pants, and I put on a jacket between my house and the office. I work (mostly) in a climate controlled environment, so I don't leave the jacket on inside, so my guns stay the same year-round.