Check the ficus to see if it is losing leaves at a rapid pace. Trees do lose leaves periodically but it is a sign of freeze damage when a ficus begins losing leaves in large numbers.
Search for brown spots and dead branches on the ficus. This indicates that the freeze killed the branches. Simply because your tree has freeze damage does not mean it is completely dead. Sometimes freeze damage occurs only to leaves or to certain branches of the tree.
Scratch brown, dead looking branches with your thumbnail and take note of the color beneath the scratch. A green layer beneath the scratch means the branch is healthy and did not freeze. Brown or black beneath the scratch indicates the branch froze and needs to be removed from the tree.