Received the HD Street 750 a few days back. and the first thing I noticed is it is NOT a city street bike. Two main reasons.
1. The engine gets really hot in the start stop city traffic, I would use the word burns..... you need proper denimware to ride this in the city.
2. The clutch and gear shift is not smooth and easy as expected in a city bike, you will end up with sore and acking hands, especially the clutch which is hard, gears extremly clunky, by the time you find the neutral, its time to go.
Out on a open stretch though, its a totally different story, it will change your concept of biking.
+40 degrees is just a insane. Like riding slowly through a fire pit with out the proper protection.
If thats the case I would just stay out of the busy city.
40 C is just 104 F, a mild summer day in Phoenix, Arizona. I lived in Phoenix for 15 years and it gets up to 120 F in the summer. And I rode my bike in traffic. But yeah, hot as hades. That's why I don't live there anymore.
I am wondering what kind of expectation OP has. No bike is cool in use on a 40 degree C day. My K bike leaves burns on my legs when ridden in those temps, and that is just from heat radiating off the engine, not from direct contact with anything.