  We use the Matrix formalism to investigate what happens to strings above the
Hagedorn temperaure. We show that it is not a limiting temperature but a
temperature at which the continuum string picture breaks down. We study a
collection of $N$ D-0-branes arranged to form a string having $N$ units of
light cone momentum. We find that at high temperatures the favoured phase is
one where the string world sheet has disappeared and the low energy degrees of
freedom consists of $N^2$ massless particles (``gluons''). The nature of the
transition is very similar to the deconfinement transition in large-N Yang
Mills theories.
