Impressive but unsustainable? At those temps the case gets so hot, wouldn't the cables begin to melt and life of the miner drastically reduce?
Also is there a point to doing this is if extra power draw negates the increased hashing power?
It looks like it would be a great setup for liquid cooling though.
The cables are rated for 125C heat. It is good to remember that the frequency can be varied based on temperature to keep below any threshold. With 35C current summer temps, it is clear that this method would be very effective during the winter.
Of course, it uses extra power, but it is still proportional. So for example instead of $4 profit - $2 electricity you can have $6 profit - $3 electricity and increase your profits by 150%.
Lastly if a board dies on a miner and warranty replacement is not possible, you can recover much of the hashrate using this method to have at least 12th left over, not far from the original 13.5th.