  We construct a traversable wormhole from a charged AdS black hole by adding a
coupling between the two boundary theories. We investigate how the effect of
this deformation behaves in the extremal limit of the black hole. The black
holes have finite entropy but an infinitely long throat in the extremal limit.
We argue that it is still possible to make the throat traversable even in the
extremal limit, but this requires either tuning the field for which we add a
boundary coupling close to an instability threshold or scaling the strength of
the coupling inversely with the temperature. In the latter case we show that
the amount of information that can be sent through the wormhole scales with the
entropy.
