While computers are handy gadgets to have, a computer's achilles' heel will always be heat. Heat literary kills the performance of a computer, including smaller versions like the Raspberry Pi and the Asus Tinker Board.
With desktop computers, there are dozens of easy solutions you can implement to keep a desktop computer cooler such as installing a water cooling kit, but with tiny computers you can't.
The main reason you don't want an overheating tiny board is because the SD card will get damaged/corrected when exceeding and working at constant temperatures above 85C.
There are even reports of Raspberry Pi 3 boards SD cards catching fire because of the SD card failing inside the Pi board.

It appears that the Raspberry Pi 3 board has an overheating problem due to it being factory overclocked beyond manufacturers' guidelines.
Whichever the case maybe, it is a good idea to integrate a cooling system of some type to prevent reduced lifespan due to overheating, especially if you own the newest PI and Tinker S boards which generate more heat than previous generations.
Fortunately, there are cool ways to manage the temperature of a Pi board and Tinker board such as using an aluminium case which is not only durable but it also does a better job than a thermoplastic case at dissipating heat.
The aluminum case you see pictured is the Akasa A-RA03-M1B model which comes with full Input / Output support and a thermal kit.
The Akasa A-RA03-M1B case is an upgraded version of the A-RA01-M1B case model so you get additional features such as finned top panel, thermal kit, cut outs and openings for an external antenna, GPIO, camera and display connectors.
Other than the finned top panel, the Akasa A-RA03-M1B aluminum thermal case looks virtually identical to the A-RA01-M1B model but slightly larger. You get the same black sandblasting anodized aluminium body which is nice.
The Akasa A-RA03-M1B aluminum thermal case measures 92 mm long, 68.3 mm wide and 33.35 mm high so it's 4 mm higher and 0.3 mm wider to accommodate the Raspberry Pi 3 Model B+, Raspberry Pi 3 Model B and the Raspberry Pi 2 Model B, as well as the Asus Tinker Board and Asus Tinker Board S.
The finned top lid in the Akasa A-RA03-M1B aluminum thermal case has a heatsink design that lets heat dissipate to cool the enclosure.
The thermal kit included with the Akasa A-RA03-M1B aluminum case passively cools the board via thermal gap fillers and CPU thermal modules.
Included are also the screws and standoffs, as well as a case body, bottom and top plates needed to assemble the aluminium case and secure the board to the case. Assembly is straightforward and doesn't take longer than 5 minutes.