The usefulness of low temperatures – achieved by applying snow, ice or ice water to the bruised area – in medicine was already known in ancient Egypt and was documented in Hippocrates’ writings. Modern cryotherapy is based on principles identified in 1978 by Japanese doctor T. Yamauchi, who was responsible for the first cold chamber for the treatment of rheumatoid arthritis.

The idea, which was taken up in Germany for the treatment of other chronic inflammatory diseases, has led modern medicine to the use of cryotherapy in the treatment and prevention of musculoskeletal, dermatological, gastroenteric, and nervous pathologies.

Localised cryotherapy i.e., the application of low temperatures to specific body areas has several effects:

• Analgesic effect: achieved by slowing down the nerve conduction of nociceptive fibres, which in turn inhibits the transmission of algic neurotransmitters in the dorsal horn of the spinal cord
• Myorelaxant effect: the decrease in input from sensory nerve fibres leads to muscle relaxation and resolution of the cramp, increasing the analgesic effect in the treated area
• Haemodynamic effect: thanks to the vasoconstriction induced by the drop in temperature
• Metabolic effect: achieved by reducing the extent of ischaemic damage due to hypoxia

Cryotherapy is widely used in sports medicine. The effects of cryotherapy derive from the intensity of the cold and the duration, frequency, and method of application. For racehorses, the application of cold is well-known in the treatment of musculoskeletal injuries.

• Acute injuries: induced vasoconstriction reduces the recall and extravasation of inflammatory mediators, thus decreasing phlogosis
• Chronic injuries: the alternation of hot/cold applications accelerates the reparative processes and tissue healing

As an adjuvant during the first steps of rehabilitation, the application of localised cold immediately after exercise effectively limits pain and soreness in the part.

Cryotherapy has also proved to be beneficial in the treatment and prevention of laminitis, especially endocrine and endotoxic laminitis. Cryotherapy sessions should last no more than 20 minutes – after which vasodilatory phenomena begin to be observed – to achieve a temperature of the affected area of between 10 and 15 degrees Celsius. The methods used to achieve this effect range from ineffective ice showers to the immersion of the part in ice water, the application of ice packs or ice shin guards, or the purchase of specialised equipment.