  Despite compelling evidence to the contrary in recent years, the view still
persists that quantum effects cannot survive very long within a warm, noisy and
complex environment that washes out quantum effects at timescales far too short
for any chemically or biochemically interesting processes. It is also assumed
that as the temperature of the surrounding environment increases, so the
efficiency of processes such as quantum tunnelling drops. One way of viewing
this has been to invoke the quantum Zeno effect: that the watched pot never
boils. In this work we show that the opposite is true. For a quite general open
quantum system, a proton in an asymmetric double-well potential, the action of
the environment is to enhance the tunnelling rate (an anti-Zeno effect). We
compare two simple mathematical models to show that, over a specific
temperature range, thermally enhanced quantum tunnelling is equivalent to
increasing the frequency of a von Neumann-type measurement by the environment
on the system.
