Mikhailtech posted a review on the Vizo Orbiter HDD Cooler

The past few years hard drives have grown exponentially in capacity and cache size (as well as new features like NCQ), but the most common spin
rate is still 7200RPM. Another variable that hasn't changed much is heat
output: a lot of drives still manage to get quite warm under normal conditions. Though placing one directly behind an intake fan in a case often solves the problem, it's a solution that's not always available. Some users also
feel safer knowing that their drive is getting that extra bit of cooling.
Either way, you have one other option: an HDD cooler. Today we'll be taking a
look at Vizo's Orbiter, a simple, easy to install, single fan blower.

Vizo Orbiter HDD Cooler Review