  We study the conductance statistical features of ballistic electrons flowing
through a chaotic quantum dot. We show how the temperature affects the
universal conductance fluctuations by analyzing the influence of dephasing and
thermal smearing. This leads us to two main findings. First, we show that the
energy correlations in the transmission, which were overlooked so far, are
important for calculating the variance and higher moments of the conductance.
Second, we show that there is an ambiguity in the method of determination of
the dephasing rate from the size of the of the weak localization. We find that
the dephasing times obtained at low temperatures from quantum dots are
underestimated.
