Can be a worry when they are tiny hatchlings , very easy for them to disappear under a door , or bed or behind a big heavy walldrove or cabinet.
I would make sure you have hold of his tail at all time (just the weight of your wrist on the tail is enough to slow a little hatchling down) , plus have a hand ready to place infront of the hatchling if looks like make a leap or short sprint.
If he gets onto the floor, easiest way to catch him is to drop a tea towel or shirt or some thing large and light on top of him, you can then reach under and get hold of him without scaring the heck out of him by chasing him and trying to grab him .... all he's see is big scary monster looming over him and a 5 headed monster coming for him ....
Block off any gaps between furnature and walls with towels or bits of cardboard, and make sure the door and window are closed and he'll be fine if he decides to go exploring.
There are beardie harnesses and leashed available too , some use these for the added security.
Been my experience with my pet lizards that if they happen to get into the floor (and have never been wild or allowed to free range) that they'll generally not go far, it's kinda like " Oh , now I'm here , I'm not so sure I want be - it's strange/scary down here and everything looks different ", I can usually reach down and scoop up the errand lizard without any dramas and they seem relieved be rescued when I do.