Netatmo Doorbell Overheating

Since the mid of June my Doorbell stops working because of heat.

It always appear between 12 - 4pm, yes its located in direct sunlight south sided.

But it's a doorbell, its meant to be outside.

Any chance to apply a fix? Is there a better cooling solution available, a copperpad for the cpu or something else?

I have no worries to open it up myself but since the HKSV support failed, after it was announced, this is the next regret i got from this device.