First Ice Age

The First Ice Age on Earth occurred in the time of Neanderthals. (TV: Ghost Light; AUDIO: The Exxilons) During this time, an Ice Warrior craft from Mars crashed and buried itself. (TV: The Ice Warriors) One Neanderthal was preserved by Light. (TV: Ghost Light) The Dæmons visited Earth, and according to the Third Doctor, inspired cave paintings of powerful supernatural beings. They favoured humans over Neanderthals, causing the latter to die out. (TV: The Dæmons)

The First Doctor visited Earth during the Ice Age, where he encountered a monster. (COMIC: The Ice-Age Monster)

In Birmingham during the Ice Age, the Eleventh Doctor and Amy Pond saved a group of Neanderthals who were being experimented upon by aliens. (COMIC: Snow Globe)

When Amy made a smart remark about the Doctor's suit, he warned her that the Ice Age was "a click away on the dial". (GAME: City of the Daleks)

When Majenta Pryce tried to activate the SKARDIS, it released a chronal wave which froze Sydney in ice from the Ice Age. (COMIC: The Age of Ice)

When Danny Pink asked how a tree could naturally grow in one night, the Twelfth Doctor claimed that a similar question was asked about the Ice Age: (TV: In the Forest of the Night) "How can whole glaciers just pop up out of nowhere? Well, they just did. That's how this planet grows - a series of catastrophes. Farewell to the Ice Age. Welcome to the Tree Age. Possibly. When the Ice Age was here, you lot managed to cook mammoth. Now there's a forest, you'll just have to eat nuts."

- The Twelfth Doctor

Thousands of years later came the Second Ice Age, circa 5000. (TV: The Ice Warriors, The Talons of Weng-Chiang)