A Very Hot Tunnel                                      -      -      - 
(-------------------------------------------------)     W <---(M)---> -
                                                        -      S      -

The temperature in this section of the tunnel is much higher than in the
rest of the area.  You can hear a faint roaring sound from below, and out of
curiousity you place your hand on the ground.  However, you immediately jerk
it back, since the floor is burning hot.  The tunnel continues to the west,
and leads back to a cooler chamber to the south.