  Materials hosting tilted Dirac/Weyl fermions provide an emergent spacetime
structure for the solid state physics. They admit a geometric description in
terms of an effective spacetime metric. Using this metric that is rooted in the
long-distance behavior of the underlying lattice, we formulate the hydrodynamic
theory for tilted Dirac/Weyl materials in $2+1$ spacetime dimensions. We find
that the mingling of space and time through the off-diagonal components of the
metric gives rise to: (i) heat and electric currents in response to the
$temporal$ gradient of temperature, $\partial_t T$ and (ii) a non-zero
symmetric Hall-like conductance $\sigma^{ij}\propto \zeta^i\zeta^j$ where
$\zeta^j$ parameterize the tilt in $j$'th space direction. The finding (i)
above that can be demonstrated in the laboratory in state of the art
cooling/heating rate settings, implies that the non-trivial emergent spacetime
geometry in these materials empowers them with a fascinating capability to
harvest the naturally available sources of $\partial_t T$ of hot deserts to
produce electric energy. We further find a tilt-induced contribution to the
conductivity which is an offspring of Drude pole and can be experimentally
disentangled from the Drude pole itself.
