Stupid....but plz answer?

so i usually buy my lunch but tomorrow im taking. my school has no A/C and it is a brick oven. it's about 90 degrees out so my locker's gonna get pretty woram. my lunch box is inselated and i have ice packs but when i do take my lunch it ends u[p all soggy. im taking a wawa hoagie. what can i do to make it not soggy?