A magic sponge is a sponge

Sponge (tool)

A sponge is a tool, implement, utensil or cleaning aid consisting of porous material. Sponges are used for cleaning impervious surfaces. They are especially good absorbers of water and water-based solutions....

 soaked in very hot or cold water applied to sports injuries

Sports injuries

Sports injuries are injuries that occur in athletic activities. In many cases, these types of injuries are often due to overuse or acute trauma of a part of the body when participating in a certain activity. For example, runner's knee is a painful condition generally associated with running, while...

 in order to reduce inflammation

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 and pain. It was frequently used as a panacea

Panacea (medicine)

The panacea , named after the Greek goddess of healing, Panacea, also known as panchrest, was supposed to be a remedy that would cure all diseases and prolong life indefinitely...

 for such injuries. Association Football teams pioneered the use of the magic sponge as the combination of its pain relieving effects and, possibly, the placebo effect

Placebo effect

Placebo effect may refer to:* Placebo effect, the tendency of any medication or treatment, even an inert or ineffective one, to exhibit results simply because the recipient believes that it will work...

 served to get valuable players quickly back into a game.

The magic sponge is rarely employed in professional sports since the introduction of trained physiotherapists

Physical therapy

Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...

. Its function can be better fulfilled by an ice pack

Ice pack

An ice pack or gel pack is a plastic sac of ice, refrigerant gel or liquid, or, in an emergency, even frozen vegetables. The refrigerant, usually non-toxic, can absorb a considerable amount of heat, since its enthalpy of fusion is high...

 or heating pad

Heating pad

A heating pad is a pad used for warming of parts of the body in order to manage pain. Localized application of heat causes the blood vessels in that area to dilate, enhancing perfusion to the targeted tissue...

, which do not carry the risk of infections spreading between players.