by underheat he doesnt mean heat pad under them,he means not keeping them hot enough,mate monitors love to hide,moving the hide spot to the cool end wont help as he will stay hidden down there ,i use a stack under the heat lamp,my stacks consist of plywood sheets spaced out one above the other with a piece of wood between each level,so it has gaps for the monitors to squeeze into,my lot get at least 3 levels,normally between 3 an 5 levels and the basking spot ontop of the stach reaches at least 70 degrees,yes 70 degrees celcius,its just a small area ontop of the stack that gets to that temp.they frequently bask there as well,the good thing with using stacks is they offer hide spots with varing temps,obviously getting cooler each level u go down from the top,i dont use under tank heat for my lot either,its not nessacary if u have the right heat available up the top,,i also keep them hot at night but that isnt nessacary,but its best to keep them warm at night with the use of red bulbs to mimick night time,years ago i just kept day lights on 24 /7 and that worked great as well,they still knew when to sleep ect,also with basking temps that high,only on the raised stack area if they get to hot they go lower in there stacks,hence why i dont use under tank heat,it gives them the bottom level as a cool retreat,i also have a temp gradient to the cool end of my cage which is the room temp,so really cold over winter as there in an uninsulated tin shed in melb, and up to 30 degrees in summer heatwaves,u have to think of what monitors do in the wild,they will stay in cover if they can,they can thermoregulate from there crevices/burrows and probably aquire a lot of there food in there as well,they love heat,and thrive on it