Piping hot means so hot it is only just bearable. Piping hot soup, served piping hot, still piping hot.
It belongs to food and drink and is always approving, since piping hot is what a pie should be. The phrase is from the fourteenth century and comes from the sizzling, piping sound of food fresh from the pan.
1phrasepiping hotSo hot it is only just bearable.
“Serve the soup piping hot with fresh bread.”
piping hot is a heat.
From the fourteenth century, from the piping sound of food sizzling fresh from the pan.
From Middle English -. First attested circa second half of 14th century, from the similarity between the sizzling sound of food cooking in a frying pan and that of musical pipes, from Canterbury Tales [http://www.gutenberg.org/etext/2383] by Geoffrey Chaucer:
Etymology from Wiktionary, CC BY-SA
Practised in Texture & Touch