The development of cooling technologies is progressing steadily in view of current and future challenges, for example in the field of high-performance computers, artificial intelligence, and sustainability. However, the question arises as to which technologies will be developed further and when a switch from air to liquid cooling will take place. Economic key figures are hardly accessible, and the technologies are practically not included in generally accessible databases. With one exception: the patent databases. What can we learn from this source about the development of cooling technologies? How has the development progresses over time and what is the mix of technologies?