External warming: Use blankets, warm (not hot) water bottles, or heating pads on the torso, but avoid direct heat (e.g., hot water, heating pads) to prevent burns. The warmth should be applied gradually, focusing on the trunk rather than limbs (which could cause shock).
Warm fluids: If the person is conscious, offer warm (non-alcoholic, non-caffeinated) fluids to help raise body temperature.