I've been invited to an event all day and i've decided to be brave and leave my almost 3 month old at home with his dad for the first time. However i'm breastfeeding and will need to express whilst i'm out, which i have a battery opperated pump..... But i have no access to a fridge and will be on the move, moving round the event all day. Any way i can prep and not waste the milk or purchase something to help with keeping my milk fresh?