"Gel packs" refer to small bags or containers filled with a gel-like substance that can be frozen or heated. They are often used to provide cooling or soothing relief for injuries, reduce swelling, or keep food and beverages cold. Full definition
Ice packs, freezer packs, frozen gel packs and other accessories required to cool breastmilk, formula, and juice are allowed in carry - on. (olympialactation.com)
And hot / cold gel packs, which fit inside your bra, can soothe swollen or sore breasts. (babycenter.com)
If you're breastfeeding, include breast pads, soothing gel packs for sore nipples, and a case of bottled water underneath the table for late - night thirst attacks. (pregnancymagazine.com)