How long is your commute? That may be key. Mine is only 9mi each way and made it through last summer fine, enjoyable even. Of course last summer was mild in comparision to what is typical (high was only 115., maybe a few days at 118 or so if I remember right, but not those weeks on end of 118+) Of course the air above the pavement surrounded by cars is much hotter.

I leave from home about 6:45am and from work about 5pm or so. One 24oz. bottle of plain water worked, usually finished a mile or so from home. I made sure I kept hydrated at work and after getting home.

Once moving at speed the dry heat is not so bad, but sitting a stoplights can be hot.

I use SPD sandals which keep the feet cool.

Al