This is the one I bought. I think it's absolutely superior due to the way it's constructed and it's features. Pricey, but worth it.

Icekap Migraine Cap - Patented Migraine Relief Headache Hat with 5 Gel Ice Pack - Ice Hat Lasts Up to 3 Hours! Icecap for Migraines, Chemo, Sinus Relief, Head Tension, Fever, Flu, Menopause and More https://www.amazon.com/dp/B071XT4D5S/ref=cm_sw_r_other_apa_i_dtcuEbP91KC8G

This is the one I use - https://smile.amazon.com/dp/B071XT4D5S/ref=cm_sw_r_other_apa_i_jtA0EbN0B7PVP

Has a spot for a ponytail if you need it, and you can out ice packs in at only the spots you need it or your whole head.

This is the one I use - https://smile.amazon.com/dp/B071XT4D5S/ref=cm_sw_r_other_apa_i_jtA0EbN0B7PVP

Has a spot for a ponytail if you need it, and you can out ice packs in at only the spots you need it or your whole head.