Давайте не будем путать вот эти два выражения: to be cold & to have a cold.

I am cold. - Мне холодно.

I have a cold. - У меня простуда.

Если мы говорим про кого-то другого, то просто меняем форму глаголов:

I am cold. You are cold. He is cold. She is cold. It is cold. We are cold. They are cold.

I have a cold. You have a cold. He has a cold. She has a cold. It has a cold. We have a cold. They have a cold.