1. Get ice crystals: Ice crystals can be bought in shopping centers, supermarkets or online stores. Choose the right size and shape of ice crystals to suit your ice pillow.
2. Open the ice pillow: find the opening or zipper on the ice pillow and open it. Make sure that the opening is large enough to accommodate ice crystals.
3. Add ice crystals: Carefully pour the ice crystals into the ice pillow. You can use a small funnel or handle to help prevent ice crystals from overflowing.
4. Control the number of ice crystals: according to personal preferences and the size of the ice pillow, add an appropriate amount of ice crystals. Don't fill it too full, lest the ice pillow be too hard.
The temperature of ice crystal pillow is too low: long-term use will lead to stimulation of head, brain and neck, which is not conducive to blood circulation, leading to cerebrovascular diseases and cervical spondylosis.