Usually, pumped breast milk stays fresh for at least 6 – 8 hours at room temperature (i.e., up to 77 degrees Fahrenheit). However, if you refrigerate the milk as soon as possible, then it will stay up to 24 hours. Make sure the breast milk stays all time no matter where you place it, to avoid contamination. If you are going to be pumping without a refrigerator, then consider a cool bag with ice packs. With proper insulation, breast milk will stay good for 24 hours – as long as ice packs stay in contact with the container having breast milk.