thanks for the thermometer tip Burnt Toast...it is unobserved, so that is why i am debating on using a delivery system vs. a bottle. also, slightly worried about how these arctic temperatures might affect the bottle vs the whizz while in transport...using public transportation, i might be outside 15 min prior to test, with an anticipated 30-45 min wait...it wil be one of the things i will be testing this weekend.