  Rydberg atoms feature extremely strong interactions, in particular between
states of opposite electronic parity. In a room temperature environment, these
states are inevitably populated due to black-body radiation, leading to
many-body dephasing. Here we report on a controlled microscopic study of the
resulting interactions, which we probe single atom resolved by facilitated
excitation in an optical tweezer array. We identify motion of the excited atoms
to be of prime importance for the process, which can be used to mitigate the
impact of the state contamination on 2D quantum simulators.
