Seemingly in an ice age of some description, the TARDIS controls freeze and only the hot breath of a massive dinosaur-like beast can thaw them out enough for the TARDIS to whizz back off into time and space.  The gormless image of the ice-age monster at the end of the story is delightful!

Decided to do all 16 stories of these I think there basically Ian 1st and Barbara stories the final 2 retell the webplanet with just those 3 but over all there not the best but I think if I was from the 1960s I’d love them