Is there a way to cap the temperature so my wrist are not burning? Using a MacBook Pro (Retina, 13-inch, Early 2015)
The heat of the place where the wrist are laying is annoying. 

I cannot measure the temperature of this exact part but with the help of smcfancontrol I deduced that when the cpu is about 40~45°C this part is tolerable. 

The parameters in the game are: Fan speed, CPU speed, Temperature.
Right now the fan speed is very low. Always inaudible.
I would like to trade the heat problem for more fan speed without compromising CPU speed.

Has somebody already adressed this issue ?
Try SMCFanControl for Mac.

It's what I use when my Mac gets too hot, it increases fan speed to cool the CPU and other components down pretty quickly.

You can set custom fan speeds by clicking the application's view on the menu bar (it will say something like 99°F 1199rpm) and clicking Preferences or Active Setting.