How did medieval people keep their houses warm?

Answer:

They most likely used a fireplace. they used fireplaces and chimneys to heat there houses and cook.

Answer:

Most people in the Middle Ages did not heat their houses with what we would call fireplaces because the chimney was not invented until the 11th or 12th century, and was too expensive for any but the wealthy for a long time after that. Most people dressed heavily and heated their houses with free standing fires on hearths that sat on dirt floors. The smoke was vented through a hole in the roof or high on the walls under the peaks of the roof. Some people had what are called hanging chimneys or smoke canopies to guide the smoke. In the homes of the wealthy, where the floors were likely to be wood or tile, braziers were used, and the holes in the roof were more elaborately set up so rain would not come in.