no all the steps are the same i have been using this product for 3 years and it works every time i have also done extensive studies to test how long it takes to warm when under 40 and over 40 degrees using a heating pad that keeps it warm all day for me (since mine are totally random) both 2oz and 3oz bottles have almost the exact same heating and cooling times and have worked just fine with the one hand warmer
provided by spectrum i have also used other store bought hand warmers and they work fine as well
P.S i would not use the 2 oz anymore alot of labs are wanting 3 ozs urine now last time i went in i had to smooth talk the girl into letting me slide with only 2