Hmm best not to... but if you REALLY have to then maybe you can store your pump in the fridge for your 2nd pump if there is a fridge there.. maybe pump right before you go out, then pump once while you're out around 4 hours later.. rush home and pump again asap.. would that work?
I have to pump twice at work daily without fridge.. I will pump and put parts in Ziplock and into my chiller bag.. then would reuse. No choice. My chiller bag quite cool with e many ice packs. Think it’s ur comfort level also.. All the best!
Jj