The Laptop is a Thinkad E580. I have opened it and cleaned out any dust, fresh cooling paste between heatpipes and chips, but that made no difference. Google searching for problem only returned hits for stopping or slowing the noisy fan - I needed the opposite patch with FULL speed on the fan.
It was a quick project. I just needed to push more air in through all the ventilation grilles. The exhaust is at the back edge so no worries there.
The design is a conduit that the laptop stands on, and a fan that pushes air in at the edge of the conduit. The shape covers all air inlets
The fan used was 12V, so I used a standard BoostConverter to take a USB to 7-8V to have a reasonable "pressure" and not overwhelming noise.
It works. The temperature now stays at 60° where before it climbed to 70+. More importantly the CPU stays at 3Ghz and does not throttle to 1GHz. Lastly, the laptop is not uncomfortably hot to handle even after a 3 hour gaming session.