1. Use in preparation of a medicament for treating congestive heart failure (CHF) in a human patient suffering therefrom, of an aliquot of modified blood of the patient, prepared by treating the aliquot of the patient's blood ex vivo with stressors comprising ultraviolet light and an oxidative environment. 2. Use according to claim 1, wherein the oxidative environment used in treating the blood aliquot comprises application of an oxidizing agent to the aliquot. 3. Use according to claim 2, wherein the oxidizing agent contains ozone gas, and the ozone gas is introduced into the blood aliquot in an amount which does not give rise to excessive levels of cell damage. 4. Use according to claim 2 or claim 3, wherein the oxidizing agent comprises a mixture of ozone gas and medical grade oxygen, the ozone gas being contained in the mixture in a concentration of up to about 300 ug/ml. 5. Use according to claim 4, wherein the ozone gas is contained in the mixture in a concentration of up to about 30 ug/ml. 6. Use according to claim 5, wherein the ozone gas is contained in the mixture in a concentration of from about 13.5 ug/ml to about 15.5 ug/ml. 7. Use according to claim 4, 5 or 6, wherein the mixture is applied to the aliquot at a flow rate of up to about 0.33 litres/min. 8. Use according to claim 7, wherein the mixture is applied to the aliquot at a flow rate of from about 0.21 litres/min to about 0.27 litres/min. 9. Use according to any preceding claim, wherein the ultraviolet light used in treating the blood aliquot comprises ultraviolet light having one or more UV-C band wavelengths. 10. Use according to any preceding claim, wherein the temperature to which the aliquot is cooled or heated during the treating of the blood aliquot is a temperature such that at least part of the aliquot is in the range of from about -5 degree C to about 55 degree C. 11. Use according to any preceding claim, wherein the mean temperature of the blood in the aliquot during the treating step is in the range of from about 37 degree C to about 44 degree C. 12. Use according to any preceding claim, wherein the mean temperature of the blood in the aliquot during the treating step is in the range of from about 0 degree C to about 36.5 degree C. 13. Use according to claim 12, wherein said mean temperature of the blood in the aliquot is in the range of from about 10 degree C to about 30 degree C. 14. Use according to claim 11, wherein said temperature is 42.5+-1 degree C. 15. Use according to any preceding claim, wherein the volume of the aliquot is from 0.1 to 400 ml. 16. Use according to claim 15, wherein the volume of the aliquot is from 0.1 to 100 ml. 17. Use according to claim 15, wherein the volume of the aliquot is from 5 to 15 ml. 18. Use according to any preceding claim, wherein the aliquot is treated with the stressors for a period of up to about 60 minutes. 19. Use according to claim 18, wherein the aliquot is treated with the stressors for a period of about 2 to 5 minutes. 20. Use according to any preceding claim, wherein the aliquot is treated with ultraviolet light and an oxidative environment simultaneously. 21. Use in the preparation of a medicament for treatment of congestive heart failure (CHF) in a human patient suffering therefrom, of a combination of an aliquot of the patient's own blood which has treated ex vivo with one or more stressors selected from an oxidative environment, thermal stress and electromagnetic emission; and a pharmaceutical agent selected from the group consisting of nitrates, beta-blockers, ACE inhibitors, AT receptor blocking agents, aldosterone antagonists, calcium channel blocking agents, TNF blocking agents, suppressors of production of TNF-alpha, sodium and fluid restriction, diuretics and digitalis. 22. Use according to claim 21, wherein the pharmaceutical agent is a suppressor of TNF-alpha selected from the group comprising pentoxifylline, TACE inhibitors, amrinone, adenosine, thalidomide and dexamethasone. 23. Use according to claim 21 or 22, wherein the stressors comprise ultraviolet light and an oxidative environment applied simultaneously to the blood aliquot ex vivo. 24. Use according to claim 23 wherein the oxidative environment comprises a mixture of medical grade oxygen and ozone bubbled through the blood aliquot, and the ultraviolet light comprises ultraviolet light having one or more UV-C band wavelength, applied simultaneously to the blood aliquot ex vivo whilst the blood in the aliquot has a mean temperature in the range from 37 degree C to 55 degree C.