This Steam Deck dock has a thermoelectric cooler

Much like the official dock, Unitek's version cushions your Steam Deck — or any portable device, for that matter — with a strip of soft silicone, and there's a short USB-C cable dangling from the back for connecting to the console. The thermoelectric cooler, RGB-lit fan and metallic contact plate are all housed within a hinged module, which allows for minor tilt angle adjustment while supporting the Steam Deck.
Much like the official dock, Unitek's version cushions your Steam Deck — or any portable device, for that matter — with a strip of soft

Conelz For Steam Deck Fan Cooler,SteamDeck Heatsink,Cooling fan with Built-in battery LED Quiet 3M magnetic semiconductor - AliExpress

Valve announces the SteamDeck, Page 179

Let your Steam Deck chill with this dock that features thermoelectric cooling

Cooling Dock Pro for ROG Ally/ Steam Deck

This Steam Deck dock has a thermoelectric cooler

Conelz For Steam Deck Fan Cooler,SteamDeck Heatsink,Cooling fan with Built-in battery LED Quiet 3M magnetic semiconductor - AliExpress

Unitek's Cooler Dock Pro for Steam Deck Will Keep Your Device from Ove

How to fix Steam Deck overheating problem(shut down, fps drops, etc…)? – EasySMX