There's a soup kitchen at Wall and Temple Streets near New Haven Green called Downtown Evening Soup Kitchen (DESK). Hot meal, and a chance to socialize.

Keep a window cracked open in your vehicle on the street side, not sidewalk side, to let moisture out. Fogged up windows draws a ton of attention, and the mold/mildew that grow in the moist environment is dangerous to your lungs. If you have a sunroof, leaving it cracked open while you're away from vehicle will help air it out without inviting thieves.