I try to show up to work early so I can cool off and get some cold water in me. I also bring ice water with me, but it tends to be HOT by the time I get to work. It's been working for me, but my commute in is pretty much down hill most of the way. A few hills towards the end I guess, but nothing too serious. The commute home is probably where I'm at the worst risk for heat stroke or exhaustion. I tend to fly home, and the traffic is thicker, so you get the heat radiating off of every car. It's like being inside an oven inside a hot room.

It's been killer a few times, but I try to drink a lot of water and once I get home I go straight to the shower. How far do you have to commute? I know the hills can be pretty annoying out there in Central MA.