Every object, whatever its temperature, emits electromagnetic radiation. You, a cup of tea and a block of ice all do it. Objects at everyday temperatures emit mostly infrared, which our eyes cannot detect, so we do not see them glow.
The temperature of the object controls two things about its emission. The first is the intensity, the power emitted per unit of surface area. The intensity increases at every wavelength as the object gets hotter. The second is the wavelength distribution. An object emits a range of wavelengths, not just one, and the wavelength at which the most radiation is emitted gets shorter as the temperature rises.
This is why a heated metal poker first glows dull red, then orange, then white. As it gets hotter the peak moves from the infrared towards shorter visible wavelengths. The Sun, with a surface temperature of about 6000 °C, emits most strongly in the visible region, and it also emits ultraviolet and infrared. A cool object at room temperature peaks in the infrared.