Since Zerodol P (which contains aceclofenac and paracetamol) hasn't lowered his temperature, please do not give him any more medication immediately to avoid an overdose. Instead, focus on cooling him down naturally by applying cool, damp cloths to his forehead, underarms, and groin. Ensure he sips water or electrolyte solutions, as heavy work can cause severe dehydration. Please keep him in a cool, well-ventilated room. Because a high fever and chills after intense physical exertion can sometimes indicate heat illness or an infection, it is best to consult a doctor promptly for a proper evaluation.