  We report the results of a new \textit{XMM-Newton} observation of the
helium-rich hot subdwarf BD+37$^{\circ}$442 carried out in February 2016. The
possible periodicity at 19 s seen in a 2011 shorter observation is not
confirmed, thus dismissing the evidence for a binary nature. This implies that
the observed soft X-ray emission, with a luminosity of a few 10$^{31}$
ergs$^{-1}$, originates in BD+37$^{\circ}$442 itself, rather than in an
accreting neutron star companion. The X-ray spectrum is well fit by thermal
plasma emission with a temperature of 0.22 keV and non-solar element
abundances. Besides the overabundance of He, C and N already known from
optical/UV studies, the X-ray spectra indicate also a significant excess of Ne.
The soft X-ray spectrum and the ratio of X-ray to bolometric luminosity,
L$_{\rm X}$/L$_{\rm BOL}\sim2\times10^{-7}$, are similar to those observed in
massive early-type stars. This indicates that the mechanisms responsible for
plasma shock-heating can work also in the weak stellar winds (mass loss rates
$\dot M_{\rm W} \leq10^{-8}$ ${\rm M}_{\odot}$ yr$^{-1}$) of low-mass hot
stars.
