Practice not only with the heating and stashing, but also practice pouring from the sub container to a cup. Make note of the temperature drop because a temp drop is expected when transferring liquids from a warmed container into a container of cooler temp. Depending on how "cold" the empty sample cup is, the temp drop can be as much as 5 degrees F . You dont want the temp drop to be drastic to the point where the temp falls out of the acceptable temp range (90-100 F).

Perhaps to overcome this condition, I always "prewarm" the empty sample cup at the facility by tucking it under my armpit as I open the bathroom door, unzipping, etc. After pouring the sample into the cup, further temp drops are avoided when I grab several sheets of toilet paper and fabricate a makeshift "coaster" to set the filled sample cup on while I zip back up, etc.



The key to a successful sub is practice.