Function

Local anaesthesia (analgesia)
When the skin temperature goes below 15 °C, the coldness has the effect of slowing down the conduction of nervous impulses.

Anti-inflammation
A fast application of cold causes a decrease in the production of neurotransmitters, which are responsible for the inflammation. This makes it possible to decrease the quantity of the substances that cause pain with 70 to 80 %, which results in a less intense inflammatory reaction.

Neurological effects
As already mentioned, cold can provoke a local anaesthesia (analgesia) provided that the temperature reaches a level below 15°C. Cold also reduces muscular spasticity.

Vasomotor reactions
The cooling down of the tissue causes a fast arteriolar and capillary vasoconstriction via the reflexes (thermoregulation).
If the application of cold is carried out long enough, it will be followed by a vasodilatation. This paradoxical vasodilatation corresponds with a protective hyperaemia.