Hi,I'm assuming you are asking about treating the same area in less than 4 weeks. Primarily, the reason is to allow your body to clear the dead fat cells from the first treatment, to allow better penetration of cold to the deeper viable fat cells that are the new intended target. Treating too quickly doesn't allow you to get to those deeper cells as effectively if there are still dead cells in the way from the first treatment.
It depends on the situation! The results of Coolsculpting take around twelve weeks to become apparent: your body needs time to breakdown and excrete the fat-cells that have been permanently killed and removed from the treatment area.If you have your treatments in two different areas (for example flanks, followed by thighs four weeks later), then there’s no problem at all. Similarly, some clients have overlapping areas treated on the same day (for example, upper and lower abdomen, with a small overlapping area of fat), or even have the same area treated twice on the same day. These two situations are not a problem. A problem may arise however if you begin a new treatment cycle on the same body area before the full effects of the last treatment cycle are seen. The treating specialist won’t be able to tell exactly which areas have been treated, and there is a higher chance of an uneven result. Good luck with your treatment.