Using containers of frozen water, rather than loose ice, also has the advantage that it leaves you with bottles of ice-water for drinking. Also, I take all the items that can stand freezing and throw them into my home deep freeze a couple of days before a long trip, and keep everything out of the icebox that doesn't absolutely need to be in there (fruit, eggs, et cetera). That way, there is actually a lot more ice in the box at the start of a trip (in the bottles of ice AND in the frozen food), and relatively warm stuff that doesn't need to be kept cold for a few days doesn't add energy (heat) to the box.
Never forget them. Do something to prevent it from happening again.
Charlotte Bacon, Daniel Barden, Rachel Davino, Olivia Josephine Gay, Ana M. Marquez-Greene, Dylan Hockley, Dawn Hochsprung, Madeleine F. Hsu, Catherine V. Hubbard, Chase Kowalski, Jesse Lewis, James Mattioli , Grace McDonnell, Anne Marie Murphy, Emilie Parker, Jack Pinto, Noah Pozner, Caroline Previdi, Jessica Rekos, Avielle Richman, Lauren Rousseau, Mary Sherlach, Victoria Soto, Benjamin Wheeler, Allison N. Wyatt