  We construct globally defined in time, unbounded positive solutions to the
energy-critical heat equation in dimension three $$ u_t = \Delta u + u^5 ,
\quad {\mbox {in}} \quad \R^3 \times (0,\infty), \ \ u(x, 0)= u_0 (x)\inn \R^3.
$$ For each $\gamma>1$ we find initial data (not necessarily radially
symmetric) with
  $\lim\limits_{r \to \infty} |x|^\gamma u_0 (x) >0$ such that as $t \to
\infty$ $$
  \| u(\cdot ,t ) \|_\infty \sim t^{\gamma-1 \over 2} , \quad {\mbox {if}}
\quad 1<\gamma <2, \quad \| u(\cdot ,t ) \|_\infty \sim \sqrt{t}, \quad {\mbox
{if}} \quad \gamma >2, \quad $$ and $$ \| u(\cdot , t)\|_\infty \sim \sqrt{t}\,
(\ln t )^{-1} , \quad {\mbox {if}} \quad \gamma = 2. $$ Furthermore we show
that this infinite time blow-up is co-dimensional one stable. The existence of
such solutions was conjectured by Fila and King.
