  We demonstrate that the Bell test cannot be realized at finite temperatures
in the vast majority of electronic setups proposed previously for quantum
entanglement generation. This fundamental difficulty is shown to originate in a
finite probability of quasiparticle emission from Fermi-sea detectors. In order
to overcome the feedback problem, we suggest a detection strategy, which takes
advantage of a resonant coupling to the quasiparticle drains. Unlike other
proposals, the designed Bell test provides a possibility to determine the
critical temperature for entanglement production in the solid state.
