An ice age is read as a very long stretch of coldness or dormancy — feelings or projects on hold for years. Tradition also sees in it the slow endurance that waits out any winter.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.