  Hill et al. have recently measured both the thermal and charge conductivities
in the normal state of a high temperature superconductor. Based on the
vanishing of the Wiedemann-Franz ratio in the extrapolated zero temperature
limit, they conclude that the charge carriers in this material are not
fermionic. Here I make a simple observation that the prefactor in the
temperature dependence of the measured thermal conductivity is unusually large,
corresponding to an extremely small energy scale $T_0 \approx 0.15$ K. I argue
that $T_0$ should be interpreted as a collective scale. Based on
model-independent considerations, I also argue that the experiment leads to two
possibilities: 1) The charge-carrying excitations are non-fermionic. And much
of the heat current is in fact carried by distinctive charge-neutral
excitations; 2) The charge-carrying excitations are fermionic, but a subtle
ordering transition occurs at $T_0$.
