It's used to tape heat cord or heat mats in place. It has a high tolerance for heat and is water resistant, so it's quite handy.
We used the tape to secure heat cord to a tile, and then covered that with another tile before placing the tiles under our hatchling's enclosures. This was a much cheaper alternative to using heat mats with each enclosure (we've got three), and it's less likely to have a fault and cause the plastic enclosures to melt. The tiles also give off an even spread of heat, without significant hot spots.
We also found the tape near aircon ducting/roof insulation.