Jolie, a special envoy for the U.N. refugee agency, was speaking in the Turkish capital Ankara on Friday, a day after she visited refugee camps along the border with Syria.
Jolie says that with the conflict in Syria showing no sign of abating, the coming winter is "a very large concern for all of us."
She says she hopes "no one freezes to death in this very frightening time."
Turkey is hosting about 80,000 Syrians who have fled the 18-month conflict in their country. Earlier this week, Jolie and UNHCR chief Antonio Guterres visited refugees in Jordan to draw attention to the crisis.