It's really frickin' hot in much of the US. Fortunately, we have central air at home, A/C in the car, and convenient local businesses with air conditioning and free wi-fi. The inadequate HVAC systems in the Science and Engineering building on campus aren't anywhere near being able to cope with this, so I'm working from home or a cafe until the weather breaks.
I will, however, use this as a shameless plug to re-link a post from last year, where we scientifically tested whether it's better to leave your car windows open or closed on a hot day. The answer: if it's a short stop, closing the windows will hold the cold air in, while opening them leads to faster initial heating. For the full-on SCIENCE! you need to click the link, though.