It is recommended to apply ice as soon as possible after tendinitis symptoms appear. Is icing quickly after the injury much more effective than after a while (e.g. a few days), and if so why?
This Yahoo answer post by Susan says :
Apply ice in the first 48 hours following an injury is effective in that it will constrict blood vessels, thereby limiting fluid rushing to the area and reducing swelling. The cold can also be helpful in pain reduction. With an injury, a knee included, the R.I.C.E. method is best to employ- Rest, Ice, Compression and Elevation. Rest the area, apply Ice (15-20 minutes at a time, never directly on the skin and always allowing the skin to return to normal body temperature before reapplication- this usually means waiting at least 60 minutes between applications), Compression as in an Ace bandage or similar wrap and Elevating the affected limb on pillows or in a sling above the level of the heart. You can take Acetaminophen or Ibuprofen for pain relief with Ibuprofen being the better choice due to its anti-inflammatory properties. It is best to take it with food.
Icing an injury will not stiffen a joint.
The cons to icing an injury are leaving the ice on for too long a period of time or icing the injury beyond the first 48 hours. After the first 48 hours, moist heat should be used.
If the patient is undergoing Physical Therapy, often the Therapist will begin the session with moist heat to relax and loosen the area to be worked and after going through exercises they may apply ice briefly in closing.
But does not give a reference.