Brain freezes commonly happen when something cold touches the roof of the mouth (your palate), which in turn causes your blood vessels to dilate rapidly to let blood flow to the area to warm it up. It’s the dilation of the blood vessels that triggers the headache pain, which shows up after only about 10 seconds and lasts 20-30 seconds.
You can prevent having a brain freeze by eating or drinking your cold treat more slowly. It’s also helpful to keep the cold substance in your mouth long enough for your mouth to become used to the temperature.
Once you have brain freeze, you can get rid of it by quickly warming the roof of your mouth by pressing your tongue against the roof of your mouth or drinking something warm. You can also place your hand over your mouth and nose and warm your mouth by breathing quickly into your hand.
So even though the weather is turning cold, as long as you quickly eat or drink something very cold, your brain freezes will not go out of season.