I have a brand-new Synapse 19, love it. But I carry my coffee to work every day, and find that the heat from the double-walled Hydroflask is transferring to the bag's large compartment, and today it unfortunately warmed my lunch. Any ideas? Is there a foam sleeve you know of? I live a couple of blocks from Paragon sports in NYC, so will look there, but I'm curious what Synapse owners have done.
Tim