We aim for a skin temperature of 41 to 46 degrees max ifwe aretrying to tighten skin. Lower temperatures can be achieved to stimulate protein production from fibroblasts without tightening. These temperatures coorelate with 66 to 71 degrees Fahrenheit within the deep dermis, which is enough to cause collagen contraction and stimulation of protein production.
Have not seen any problems.
We try to heat the skin to between 38 and 40 degrees centigrade. This is the temperature range that seems to stimulate new collagen. It should not decrease fat. This is a non invasive and painless procedure with limited but real results. I have attached a link.