A liquid cooling system is a unique feature of any phone. This is a feature that protects the phone from overheating. By this, the phone itself remains normal. That phone will not heat up even during heavy work.
One of the latest phones from Oppo, the Oppo A97 phone, has received good response regarding features and price. One thing to note is that the phone does not use a liquid cooling system.
However, even if the liquid cooling system is not used, the phone comes with a powerful processor where there is no need for a liquid cooling system. This processor is capable of handling any tough task.