  The temperature distribution of the emitting plasma is a crucial constraint
when studying the heating of solar flare footpoints. However, determining this
for impulsive phase footpoints has been difficult in the past due to
insufficient spatial resolution to resolve the footpoints from the loop
structures, and a lack of spectral and temporal coverage. We use the
capabilities of Hinode/EIS to obtain the first emission measure distributions
(EMDs) from impulsive phase footpoints in six flares. Observations with good
spectral coverage were analysed using a regularized inversion method to recover
the EMDs. We find that the EMDs all share a peak temperature of around 8 MK,
with lines formed around this temperature having emission measures peaking
between 10^28 and 10^29 cm^-5, indicating a substantial presence of plasma at
very high temperatures within the footpoints. An EMD gradient of EM(T) ~ T is
found in all events. Previous theoretical work on emission measure gradients
shows this to be consistent with a scenario in which the deposited flare energy
directly heats only the top layer of the flare chromosphere, while deeper
layers are heated by conduction.
