Why can cold drinks give us a headache?

We may finally have an explanation of this phenomenon, that you may have referred to as "brain freeze"  which is a cold stimulus headache, officially know as sphenopalatine ganglioneuralgia A team of researchers led by Havard Medical School asked 13 brave volunteers to sip ice water through a straw aimed at the roof of their mouth while an ultrasound captured the flow of blood to the brain. Their findings have shown that just before the headache hits blood rushes through the anterior cerebral artery in the brain (a front region of the brain). The evidence isn't conclusive but it's likely that the headache is in response to the extra pressure in that region of the brain, and this is our way of warming up the blood to keep our brain at the optimal temperature,