Body heat without fever can be caused by a variety of factors such as hot weather, hyperthyroidism, anxiety disorders and many others. 1. Hot weather: If the weather is too hot, wearing very thick clothes will lead to an increase in body heat, which will result in a large amount of sweat to reduce the heat, but fever symptoms will not occur. 2. Hyperthyroidism: When the level of thyroid hormone secretion is too high and the thyroid function is too hyperactive, it will promote the body’s metabolism, resulting in the production of a large amount of heat in the body, thus causing the body to heat up, but will not cause fever. 3. Anxiety: Anxiety symptoms caused by stress and other factors can lead to autonomic dysfunction in the body, which can lead to body heat but not fever. In short, there are many reasons why the body is hot but does not have a fever. If the heat persists for a long time and does not dissipate, it is necessary to go to the hospital in time to consult a doctor.