how dependable and safe are heat packs and insulated boxes for shipping ETBs and GTPs this time of the year thru Delta Dash if 2 flights are involved.(say Denver to Florida) It seems to me it would be pretty hard to ensure that the temps stay between 70 and 85...much less than 70 and they will be blowing bubbles....much more than 85 and they may cook.......is the cargo area with Das temp controlled?????? thanks