On cold days, thinking benefits from heat that does not come only from the room. Make something with your hands. Copy a passage by hand. Sketch a layout. Fold a paper model to test a shape. The posture of making changes the posture of mind.
When fingers move, attention becomes simpler. You are here with this sheet, this pencil, this line. Questions that seemed abstract gain edges you can feel. The work grows local, and local work is easier to complete. You can turn a page, and with it, a problem.
Keep the scale humble. Finish in a single sitting. Place the result where you can see it later. The object becomes a small proof that thinking can become form. That is often enough to bridge a gap in a project or lift a dim hour.
When the day ends, you will have both a thought and a thing. Warmth remains in both.