carsonkeys
WKR
My brother and I just kept two pronghorn cool (almost frozen) and dry for five days and from New Mexico to Texas by simply by draining ice water, adding CUBE ice as necessary, and keeping the coolers in the shade. For 36 hours you could probably do nothing but tape it shut and be fine, but adding the extra steps (block ice, blanket, etc.) is nice insurance. I wouldn't stress about it.