Drager BG4 Statements of Fact 3 Questions taken from 2017 Drager BG4 Statements of Fact Progress Indicator: Question 8 of 15 8.  What will BEST result in the best cooling of breathing gasses? Choices: Install the gel tube/ice canister just prior to donning Install the gel tube/ice canister during benching back at the rescue station Do not use the gel tube/ice canister at all Use only partially frozen gel tube/ice canister