YOU SAID:

the fan makes the cool when it is hot

INTO JAPANESE

ファンは暑いときに涼しくなります

BACK INTO ENGLISH

Fans get cool when it's hot

INTO JAPANESE

暑いときはファンが涼しくなります

BACK INTO ENGLISH

Fans get cooler when it's hot

INTO JAPANESE

暑いときはファンが冷たくなる

BACK INTO ENGLISH

Fans get cold when it's hot

INTO JAPANESE

暑いときはファンが冷える

BACK INTO ENGLISH

Fans get cold when it's hot