Puzzle Nook Daily

From cold to warm

Turn COLD into WARM. Change exactly one letter at each step, keep all four letter positions, and make a common English word every time. Can you do it in four changes?

COLD → ____ → ____ → ____ → WARM

First hint

Change the last letter of COLD to make a word for a length of string.

See one solution

COLD → CORD → WORD → WARD → WARM.

Each neighbouring pair differs in exactly one position. All four letters in COLD differ from WARM, so at least four changes are needed; this route meets that minimum.