Autohemotherapy is "the immediate intramuscular or subcutaneous reinjection of freshly drawn autologous blood". It was used in early 1900s and abandoned later.
In its simplest form, there is no processing involved and no refrigeration or special equipment needed, except a sterile syringe and needle, and a tourniquet.
Currently is considered as an alternative medicine.
The basic practice, as described, should not be confused with any variations which may involve oxygenation, ozone treatment, ultraviolet light, or any type of processing that would occur intermediately.