RICE. Rest. Ice. Compression. Elevation.
All these are effective at decreasing the pain and swelling.
But aside from Rest, and unless you have a lot of swelling, it is unlikely that doing the ICE part will significantly speed recovery - but feeling better is good too!
Heat works if there is a component of muscle spasm to relax the muscle. If the muscle feels very tight, heat then would be a reasonable thing to try.
For the older injury - the left calf - you may want to try myofascial release. Suzanna McGee, who often posts here as sixftlion, has a couple of article on how to do it on her web site:
Calf Myofascial Release for Injury Prevention and Better Tennis Game http://www.examiner.com/article/calf...er-tennis-game
Trigger Points and Chronic Pain http://www.tennisfitnesslove.com/201.../#.UQq6M780WSo
You might even consider doing massage for your most recent injury, but definitley don't push it too much if it hurts. The massage may help relieve the muscle spasm around the area of injury (that is, IF there is an area of muscle spasm around the injury.)
[Here is the reason I think it works for more chronic injuries is that at the site of healing.
Sometimes tissues get inappropriately "glued" together - by protein bands laid down to heal the actual injury.
Some of those protein bands unfortunately also attach themselves to adjacent muscle/tendon/fascia.
Then, instead of the healed muscle smoothly gliding next to the adjacent muscle/tendon/fascia, it pulls on it instead.
Massaging the area can break down these inappropriate attachments and let the muscle freely slide past all the adjacent tissue - no longer pulling at it.]