We study the possibility of shielding a regular extremal black hole by means
of a matter thin-shell. While the surface energy density $\sigma$ on the static
shell is negative, the tangential pressures $p$ are positive, both of them
being finite when the shell approaches the black hole horizon. The
Darmois-Israel junction conditions are used to find $\sigma$ and $p$ in terms
of the radius $a$ of the shell. The surface gravitational energy $E_{S}$ is
computed, keeping track of the pressure contribution. The stability conditions
are briefly investigated.Comment: 7 pages, no figures, minor changes, published in Physics of the Dark
Universe 14 (2016) 1-