  The dependence of thermal field theory on the surface of quantization and on
the velocity of the heat bath is investigated by working in general coordinates
that are arbitrary linear combinations of the Minkowski coordinates. In the
general coordinates the metric tensor $g_{\bar{\mu\nu}}$ is non-diagonal. The
Kubo, Martin, Schwinger condition requires periodicity in thermal correlation
functions when the temporal variable changes by an amount
$-i\big/(T\sqrt{g_{\bar{00}}})$. Light front quantization fails since
$g_{\bar{00}}=0$, however various related quantizations are possible.
