That depends on the air conditioning in the library. Central air conditioning is generally used, but the cooling effect is related to the P number of air conditioning, the area of the library and the thermal insulation effect of the library.

In order to preserve books better, maintaining proper indoor temperature and humidity is one of the important conditions to prolong the life of books, so the library will definitely set a fixed value for the temperature, so when the door is always open with a large flow of people, the cooling effect will be discounted, and of course you will feel hot.