When it comes to cooling your CPU, there are multiple cooling solutions which include air coolers (active and passive), All-In-One (AIO) coolers also closed loop coolers, and open loop (also called custom loop) cooling solution. Each solution has its own pros and cons though it is safe to assume that air coolers are safe to use as compared to the other solutions due to fear of leakage which is a single most factor abstaining the users from going all hands down to the liquid cooling. The counter argument would be the bulky weight of the high end air coolers that may put stress on your motherboards.