It will always turn on (many people have requested that not to happen) but you can manually click the X button in the top to close the heatmap. Although it will just turn on again on the next duplication![]()
You can turn off the heat map simply by clicking on the rotating radar screen whenever you have anything you want to place selected that uses it , bottom left of your UI . Sadly though it turns on every time you try and place anything that needs a heat map