Heating connective tissue can make collagen fibres contract and can stimulate connective tissue cells to produce more collagen. Above a certain temperature fat tissue or sweat glands can be reduced.
A little bit of local anaesthesia makes puncturing the skin painless. A thin, sterile rod with a metal, blunt tip and an insulated shaft is carefully introduced under the skin. This is a thermocouple, that can deliver electrical current to tissues and measure local temperature precisely.
The intensity of the current is readjusted continuously by an external device, while the thermocouple slowly slides under the skin. An infrared camera provides extra control of the temperature of the skin surface.