  Quantum effects in material systems are often pronounced at low energies and
become insignificant at high temperatures. We find that, perhaps
counterintuitively, certain quantum effects may follow the opposite route and
become sharp when extrapolated to high temperature within a "classical" liquid
phase. In the current work, we suggest basic quantum bounds on relaxation (and
thermalization) times, examine kinetic theory by taking into account such
possible fundamental quantum time scales, find new general equalities
connecting semi-classical dynamics and thermodynamics to Planck's constant, and
compute current correlation functions. Our analysis suggests that, on average,
the extrapolated high temperature dynamical viscosity of general liquids may
tend to a value set by the product of the particle number density ${\sf n}$ and
Planck's constant $h$. We compare this theoretical result with experimental
measurements of an ensemble of 23 metallic fluids where this seems to indeed be
the case. The extrapolated high temperature viscosity of each of these liquids
$\eta$ divided (for each respective fluid by its value of ${\sf n} h$) veers
towards a Gaussian with an ensemble average value that is close to unity up to
an error of size $0.6 \%$. Inspired by the Eigenstate Thermalization
Hypothesis, we suggest a relation between the lowest equilibration temperature
to the melting or liquidus temperature and discuss a possible corollary
concerning the absence of finite temperature "ideal glass" transitions. We
suggest a general quantum mechanical derivation for the viscosity of glasses at
general temperatures. We invoke similar ideas to discuss other transport
properties and demonstrate how simple behaviors including resistivity
saturation and linear $T$ resistivity may appear very naturally. Our approach
suggests that minimal time lags may be present in fluid dynamics.
