This DC-DC boost module seems to be fairly popular due to its wide operational range, high power and low cost (about 3-5€ on aliexpress). It's build with an aluminium core PCB, to cool it can be attached to a heat sink with thermal adhesive tape.
It converts 9-48V to a maximum of 48V, the output power is rated at 250W but effectively limited by the max input current of 6A. The efficiency is about 90-95%.
I was curious on how it works, so I desoldered the inductor and reverese engineered the PCB. It was almost imposible to see the traces, the schematic was derived from a bunch of continuity tests, so there might not be 100% correct. Afterwards I did a quick performance test where I placed it on a small metal case. At 100W output the transistor temperature was only 45°C, at lower loads you propably won't need any extra heatsink at all. Not that this does not have over temperature protection build in, you must verify your application!