Cozy Toes: Underfloor Heating in Roman Baths
Steam rose from beneath the floor—Roman feet never touched cold stone.

Fra Carnevale (Bartolomeo di Giovanni Corradini) — "The Birth of the Virgin" (1467), public domain
Ancient Central Heating
Steam rose from beneath the floor—Roman feet never touched cold stone. This was no fantasy: it was practical engineering.
The Hypocaust: Fires Below, Warmth Above
Romans built hollow floors, supported by brick pillars, in their public baths and villas. Slaves stoked fires in adjoining rooms, sending hot air under the floors and up through clay pipes inside the walls. Archaeologists have found charred remains and soot-lined flues in sites from Bath to Herculaneum.
Some Roman baths and wealthy homes featured hypocaust systems: hollow spaces beneath the floors where slaves kept fires burning. Hot air circulated underfoot and up through flues in the walls, creating central heating long before modern radiators. Archaeologists have uncovered these systems across the empire, from Britain to Syria.