Jeremiah 36:22 - Ellicott's Commentary On The Whole Bible

Now the king sat in the winterhouse in the ninth month. — The “winterhouse” (the palaces of kings seem to have been commonly provided with such a special apartment; comp. Amos 3:15) was probably the southern wing of the palace. It was in November or December, and, as glass windows were unknown, a charcoal fire, placed after the Eastern fashion in a brazier, or earthen pot, in the middle of the room, was a necessity. So we find a fire in the court of the high priest’s palace in the raw early morning of a Passover in March or April (John 18:18).