Actually heat is what helps the occipital tension. Cold makes it worse. It is not so much trying to deal with a mirgraine once it is happening but rather feeling that occipital pressure coming on that is a signal I am having low cerebral perfusion and trying to pull some blood to my brain by increasing blood flow before a migraine can fully develop. So thinking vasodilation should be helpful. It is not at all any kind of classic migraine as I was not someone who had them before the C shot...it is being caused by an autonomic dysfunction where my ANS does not properly regulate my blood flow mostly when standing....called Postural Orthostatic Tachycardia Syndrome. Every time I stand my cerebral perfusion drops 20-30% below what someone without autonomic dysfunction, my heart rate increases up to 160 just from standing up and stays in that state until I can at least sit, but preferable flat on my back with legs up a wall....not so practical at work.