The MOSFET backscattering theory relies on a socalled "k B T " layer. In this letter, we adopt two different approaches to examine the temperature dependencies of the width spanned by this critical zone. First of all, a 55-nm channel length n-MOSFET is extensively characterized at three temperatures of 233 K, 263 K, and 298 K while undergoing a parameter decoupling/transformation process. A unique relationship is straightforwardly created and is comparable with that in the literature: The width of the "k B T " layer is proportional to the square root of temperature. The case of 77 K is also projected. Other corroborating evidence is a Monte Carlo particle simulation conducted on an 80-nm-long silicon conductor with the "k B T " layer's width proportional to the temperature in the high field region. Without adjusting any parameters, the backscattering theory is shown to work well for the demonstrated temperatures down to 77 K.