  The in-medium masses and optical potentials of $B$ and ${\bar B}$ mesons are
studied in an isospin asymmetric, strange, hot and dense hadronic environment
using a chiral effective model. The chiral $SU(3)$ model originally designed
for the light quark sector, is generalized to include the heavy quark sector
($c$ and $b$) to derive the interactions of the $B$ and ${\bar B}$ mesons with
the light hadrons. Due to large mass of bottom quark, we use only the empirical
form of these interactions for the desired purpose, while treating the bottom
degrees of freedom to be frozen in the medium. Hence, all medium effects are
due to the in-medium interaction of the light quark content of these
open-bottom mesons. Both $B$ and $\bar B$ mesons are found to experience net
attractive interactions in the medium, leading to lowering of their masses in
the medium. The mass degeneracy of particles and antiparticles, ($B^+$, $B^-$)
as well as ($B^0$, $\bar {B^0}$), is observed to be broken in the medium, due
to equal and opposite contributions from a vectorial Weinberg-Tomozawa
interaction term. Addition of hyperons to the medium lowers further the
in-medium mass for each of these four mesons, while a non-zero isospin
asymmetry is observed to break the approximate mass degeneracy of each pair of
isospin doublets. These medium effects are found to be strongly density
dependent, and bear a considerably weaker temperature dependence. The results
obtained in the present investigation are compared to predictions from the
quark-meson coupling model, heavy meson effective theory, and the QCD Sum Rule
approach.
