The temperature at which an object stops emitting heat radiation entirely is known as absolute zero, which is defined as 0 Kelvin (K) or approximately -273.15 degrees Celsius (-459.67 degrees Fahrenheit). At this temperature, the object's thermal energy is minimized, and its atoms or molecules would be in their lowest possible energy state.
In reality, achieving absolute zero is extremely challenging, if not impossible, as it represents the complete absence of thermal energy. However, as an object approaches absolute zero, its heat radiation decreases significantly, and the emitted radiation shifts to longer wavelengths, eventually becoming negligible in the observable spectrum.
It's important to note that even at very low temperatures close to absolute zero, objects can still emit some residual radiation due to quantum effects such as zero-point energy and quantum fluctuations. Nonetheless, the amount of emitted radiation becomes increasingly minimal as the temperature decreases towards absolute zero.