My personal thoughts. I travel a fair bit and ride bicycles in a number of different cities. Most often Twin Cities MN, Marco Island FL, NYC NY, Birmingham AL, Amsterdam NL, and London UK.

It is easier to prevent sweat in Amsterdam than the others. Taking off from the doctors above; Bicycling in The Netherlands is much less stressful than elsewhere, food is healthier and not as high in sodium or chemicals, nobody wears helmets or gloves, efficient upright bicycles are plentiful, there is never a feeling that you must ride faster due to motor traffic, and there are lots of great places to stop for a hydrating beer. Even on hot humid days I think these all play a role.

The other cities aren't usually impossible though. For me anyway.

Sweat is relative. I'll sweat less riding a Citibike at a moderate pace down the Hudson River Greenway on a hot humid day than if I walk the same way. I might still sweat, but less than if I'd walked.

I think bicycling would often be less sweat inducing than taking the subway depending on how long you have to spend in what sweltering station. One day last summer I was fine going in to the subway and on the air conditioned journey but I was drenched walking from the train up to the sidewalk. I don't think this caused much odor though (and I asked my wife, son, and DIL) and that is perhaps due to no opportunity for bacteria since I was not wearing a walking helmet nor was I hunched forward while walking.