It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that a (healthy) Bedouin came to the Messenger of Allah (peace and blessings be upon him), so the Prophet (peace and blessings be upon him) asked him: "Have you ever had a fever?" He asked: What is fever? The Prophet (peace and blessings be upon him) said: "It is heat that develops between the skin and the flesh." He said: No. The Prophet (peace and blessings be upon him) asked: "Have you ever had a headache?" He said: What is a headache? The Prophet (peace and blessings be upon him) said: "It is a wind that enters the head and strikes the veins." He said: No. The narrator says that when he got up and left, the Prophet (peace and blessings be upon him) said: "Whoever wishes to see a person of the people of Hell, let him look at this one."