The temperature about which a hot solid object emits infrared radiation alone is

All objects with a temperature above absolute zero emit electromagnetic radiation. According to Wien's Displacement Law, the wavelength of peak emission is inversely proportional to the absolute temperature (λ_max ∝ 1/T). At lower temperatures, the peak wavelength falls within the infrared (IR) region of the spectrum.

The Draper point (approximately 525 ℃) is the threshold temperature at which a solid object begins to emit visible light, known as incandescence. Below this temperature, the intensity of radiation in the visible spectrum is negligible, and the object emits radiation almost exclusively in the infrared range, making it invisible in the dark. Once the temperature exceeds approximately 500 ℃, the object begins to glow (red heat). Therefore, up to 500 ℃, the radiation is effectively infrared alone. At 1500 ℃, the object would be at "white heat," emitting a broad spectrum of visible light.