Ever chug ice-cold water on a hot day and feel a sharp brain freeze—wait, that’s the roof of your mouth, not your head. Different thing. But drinking very cold water can constrict blood vessels in your throat and neck, which sometimes radiates pain upward.
Your internal thermostat prefers lukewarm. Think of it as water that’s been hugged by a sleepy cat. Room temperature is the sweet spot for head-happiness. If you must drink ice water, do it slowly, like you’re defusing a bomb made of ice cubes.
