OK, it has been 90 humid degrees lately, so that is not entirely true. If you sweat standing still, you are going to sweat riding a bike. But I have not found that to be reason to stop riding or to change the way I dress. Just like I don’t stop walking outside if it is 90 degrees.
That said, I do try to dress for the weather. If I have to wear a suit and it is 90, I am going to wear the lightest most breathable suit I have whether I am riding a bike or not. Unless it is nice and cool outside (like it was today) I usually take off the jacket while biking, just like when I drive in a suit. I also ride a little slower and take more advantage of the downhills to coast instead of pedaling. Remember I like riding slow these days. I prefer to take in the sights, stop to take a photo, etc.
With all those precautions, I still end up a little sweaty by the time I get to work on really hot days. Although the City does have showers and lockers for employees who bike, I prefer not to shower. My solution is gel hand sanitizer. The stuff cools you off, kills bacteria, evaporates dry in seconds and generally has a pleasant fragrance. It also won’t spill all over like rubbing alchohol will.
My last little secret to cool off is a mini fan at my desk. I turn this on as soon as I sit down and let it blow on my face and back while I wait for my computer to boot up. After four minutes I press the plunger on my french press, pour a cup of coffee and turn off the fan, cool, dry and ready for business.