Originally Posted by Mitragorz

I'm surprised no one has mentioned asking the front desk to store your stuff in their fridge overnight, if the room doesn't have one. Doing that should keep gel-packs cold for the length of your trip. Plus, that will keep the inside of your lunchbox cold also, which means the gel-packs (or whatever you use) don't have to raise the ambient temp of the bag in addition to keeping the food cold.

I don't think I've been to a hotel that didn't have a fridge for employees.