  We study the influence of dissipation on the switching current statistics of
moderately damped Josephson junctions. Different types of both low- and high-
$T_c$ junctions with controlled damping are studied. The damping parameter of
the junctions is tuned in a wide range by changing temperature, magnetic field,
gate voltage, introducing a ferromagnetic layer or in-situ capacitive shunting.
A paradoxical collapse of switching current fluctuations occurs with increasing
$T$ in all studied junctions. The phenomenon critically depends on dissipation
in the junction and is explained by interplay of two counteracting consequences
of thermal fluctuations, which on the one hand assist in premature switching
into the resistive state and on the other hand help in retrapping back to the
superconducting state. This is one of the rare examples of anticorrelation
between temperature and fluctuation amplitude of a physically measurable
quantity.
