1
general::
Phrase(s): *warm as toast
very warm and cozy. (*Also: as ~.) • The baby will be warm as toast in that blanket. • We were as warm as toast by the side of the fire.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Comfortably warm, as in It was freezing outside, but we were warm as toast in front of the fire. Despite the British custom of serving toasted bread in a rack that rapidly cools it, this idiom originated in England, at first as hot as toast (c. 1430) and by the mid-1800s in its present form.
American Heritage Idioms