Bringing up this old thread as i've been really feeling this heat on my R1200GS 2013 LC on these hot days - especially at Motorway/Dual carriageway speeds.
I have a Mudsling, which i have read can change the airflow causing it to cook the right leg. I have installed a Wunderlich/Puig heat deflector which helps somewhat to deflect but you still feel the build up of heat on the inside. I have recently got a high temperature exhaust blanket to go around the top half/right hand side of the catalytic converter to try and reflect the heat back/stop it radiating out and upwards so much. Not yet tested it but hoping to do so this week/weekend to see how it fairs in reducing the heat output.
It is this, if anyone is interested
After a ride in the heat, i can report the heat wrap works to keep the majority of the heat off the right leg. At times there is still an updraft of heat you can feel on the lower thigh, but no where near as bad as it was before.