This is not the place to come to find temperatures over 100 degrees (38C) or sunlight that burns a hole through automobile paint. When first I met snow birds gathering up their stuff to leave the marina where my wife and I planned to spend our summer, I asked what the attraction was. Not the weather apparently because they told me horror stories of long humid summers in unsuitable houses on the various Mid Western prairies they inhabited with their grandchildren during summer vacations. It seemed a summer even on mainland Florida is breezier and fresher than one in the depths of an Iowan cornfield. I have no terms of reference for the comparison but I see the poor dears off the cruise ships dumped into the cauldron of downtown Key West and they seem to suffer even with their fancy paper fans donated by a caring cruise ship line:
They wear broad brimmed hats and baggy unbecoming shorts from which their whitewashed legs poke like picket fences and they gasp as they strut through the city. With the best will in the world I recommend they wear dark clothing. I know it seems counter intuitive in the heat and humidity of a 95 degree (35C) afternoon but many Americans are embarrassed by obvious signs of perspiration, a necessary bodily function like so many swept under the carpet of an overly sanitized culture. Or not; what do you think? 
My wife and I were at a party last weekend and the subject of air conditioning came up in a room filled with seasoned travelers. The question came up about how one acclimates to air conditioning and I made the point that when one travels in less developed countries it's rare to find oneself hopping in and out of frigidly cooled buildings and one gets used to a certain temperature and humidity level and the body adapts. I doubt this artist in front of the Hemingway House would prefer to be in an air conditioned booth...?
Old timers at the Friday night party remembered fondly "the good old days" (sigh) when Key West homes were built to take advantage of the multitudinous sea breezes with jalousied windows and broad shaded shutters. I enjoy sea breezes at my home on stilts out in the suburbs but I stilt enjoy cranking my air conditioning and keeping the inside of my home mold free. Perhaps nowadays we just have more stuff, more electronics,more books more clothes all packed tightly into our closets. People climbing the key West lighthouse in search of a view, and possibly a breeze didn't look that cool up there:
Someone used to living at street level in Old Town prefers pedal power to a car even at this time of year. The trick is to take it easy and suck down iced drinks:
Visitors just seem to get steamed more easily, as they stroll the streets looking for something to do, be it as simple as checking out the menu of the 915 restaurant, a splendid place for an outdoor table, ringside on Duval in winter, perhaps not so much in July:
A shady spot, even that provided by a simple surrey on an electric car could do the trick.
Personally I like air in my car, I cannot conceive of driving a car down here without air conditioning, and even riding the Bonneville gets to be a bit of a trial in the heat of the day, like riding into a hair dryer. 
I feel like a shark on the motorcycle- if I'm not moving I suffocate! So perhaps the best thing to do is just give up and yield oneself to the power of summer:
Or get someone beefy and strong to pull you to where you need to go: 
I wander for a while, overheating myself, while I snapped pictures that i thought might illustrate the heat of summer downtown...
...before I wandered off the Smathers beach for a few pictures of summer in a traditional vacation setting, there to sit in the shade to cool off in the sea breeze before my next appointment.
Luckily for me I was ferrying the recovering wife around so I got to ride in an air conditioned Nissan in the middle of the day. I missed the Bonneville, but it was a sacrifice I had to make. 