  We study the flux tube thickness of a generic Lattice Gauge Theory near the
deconfining phase transition. It is well known that the effective string model
predicts a logarithmic increase of the flux tube thickness as a function of the
interquark distance for any confining LGT at zero temperature. It is perhaps
less known that this same model predicts a linear increase in the vicinity of
the deconfinement transition. We present a precise derivation of this result
and compare it with a set of high precision simulations in the case of the 3d
gauge Ising model.
