Vasodilatation = opening up of vascular structures to allow the passage of more vascular and perivascular fluid. Facilitated by heat.
Vasoconstriction = the comparative reduction in size of vascular and perivascular structures, causing a reduction in the amount of schmutz flowing through your bod. Facilitated by cooling agents (i.e., ice).
Ice. Screw cold shower; not concentrated enough. A recurrant theme in my practice:...guy pulls back muscle just a little bit; guy walks into jacuzzi for symptom relief; guy barely crawls out of jacuzzi because the heat has drawn in so much inflammation, that the fluid volume alone has become a space occupying lesion, causing nerve root compression and radicular pain (remember: fluid is non-compressable...it's why hydraulics work).
I either need to encourage all people with minor sprain/strain injuries to crawl into the hot tub or shower, and hand them my card so they're in the next day (with the assistance from someone else, since they cannot walk on their own) and enjoy counting the cash...or tell them all to stay OUT of the heat, and put an ice pack over the injury site for 15-20 minutes, every hour on the hour. Of course, that information will keep me poor, because they will feel better, and stay out of my office.
Shhhhh.
Dave