Nugget,
Regarding the thermal/Infrared camera in exploring Japs tunnels?...BEWARE...YOU MAY NEVER LIKE IT...WHAT YOU WILL SEE....
In late 1990's....our team explored one of the Japs tunnels in Montalban town. Since flashlight batteries doesn't last long....my treasure hunter friend turn on the infrared camera as our only source of vision while walking inside the tunnel...infront of the line is the infrared camera man and the next are 5 members holding each others shoulder walking like blindman inside tunnel...while grouping and walking blindly...one of my friend are joking that there are ghost in these tunnel...we just ignored him...
Suddenly while grouping and walking almost blindly inside the tunnel...we heard very clear moaning and marching sound....suddenly the lead man with infrared camera...saw something and shouted at the top of his voice...JAPS SOLDIERS GHOST !!!....ALL HELL BROKE LOSE..

.....just imagine 6 of you...blindly running and shouting inside very dark tunnel...all of us got...bruises and bumps when we get out of the tunnel...
When we reviewed the tape of the camera....it is indeed very clear the moaning and marching sound....and white cloud walking formation (Japs ghost)....
Since then....every time we enter japs tunnel...we pray, carry lots of lights (candles,flashlight, lamps, etc)....and never again joke or challenge the exsistence of Japs ghost inside the tunnel...bcoz they do exist...
Hazard of the trade...