Hey there, Steve!
Welcome to the Disney Parks Moms Panel!
Guests are allowed to bring a cooler on wheels as long as it is smaller than 24x15x18, as you mentioned. Most of the soft-sided coolers are well under
this requirement, so you and your family are more than welcome to fill up your cooler with fruit, chips, sandwiches, bottled water, and other foods that do not require warming!
Also, security will check this cooler, along with other bags, before you enter each park.
Enjoy planning the rest of your upcoming Disney vacation and loading that cooler with some of your favorite food items!
If you have additional questions, we're here to help supply you with as much pixie dust as you can handle!!
See you real soon!
Korliss