OCC has published a review on the Sapphire Radeon HD 5850 Toxic OC Edition

The cooling solution used is Sapphire's proprietary Vapor chamber cooling solution that goes by the name Vapor-X. The cooling solution uses three heatpipes, in addition to the Vapor Chamber, to efficiently pull the thermal load out of the GPU and memory. With the driver controlling the fan speeds, I saw temperatures in the 57 to 59 degree Celsius range, where the reference card I tested came in at 66 degrees Celsius under load. When overclocked, the Toxic peaked at 49 degrees Celsius.

Sapphire Radeon HD 5850 Toxic OC Edition Review