Q&A: How Long My Milk Last?
Breast milk can stay fresh for six to eight hours at room temperature (up to 77 degrees Fahrenheit). But if you can, be sure to stick it in the fridge or freezer as soon as possible, and always keep the container closed to prevent the introduction of bacteria. If you know you'll be pumping without a refrigerator nearby, consider taking along a cooler bag with ice packs. Breast milk will stay good up to 24 hours in an insulated cooler, as long as you keep the ice packs in contact with the milk and try not to open the bag too often.