The Progressive Era. During the period known as the Progressive Era (1890s to about 1920) the U.S. government became increasingly activist in both domestic and foreign policy.
One possible link between brain freeze and other headaches is local changes in brain blood flow. If further research confirms all these types of headaches are caused by blood flow changes, new drugs that block widening of the blood vessels - called vasodilation - could improve treatment for sufferers.
There are two common causes for freeze-up, and one is less expensive to fix than the other. The first cause is a freon leak in the system. When a freon leak is present, the coils can cool unevenly with some parts of the coil staying extremely cold for a long time. This leads to build-up of ice on the coil from the moisture extracted from humid air passing over it.