O'Brien's words about never being warm again after cold sleep returned to him.

No one had ever been in cold sleep for eight hundred years.

On the bed, Elizabeth lay still, in the cold sleep of death.

Even leaving such a being in cold sleep was a risk.

You'll spend perhaps twenty years awake and the rest in cold sleep.

"I just want to be put back into cold sleep."

"Can't we put the crew in cold sleep and take them with us?"

Ever since we came from cold sleep three weeks ago, I've sensed something different.

Otherwise you could not survive ten years in cold sleep.

The four Disciples had been the last to go into cold sleep.