YOU SAID:

you know it's cold outside, when you go outside and it's cold

INTO JAPANESE

外に出て寒いときは、外は寒い

BACK INTO ENGLISH

When it's cold to go outside, it's cold outside

INTO JAPANESE

外に出るのが寒いときは外が寒い

BACK INTO ENGLISH

When it's cold to go outside, it's cold outside