Mine Rescue Field Exam From the 2013 North Central Regional Mine Rescue Contest, Wilmington, IL Progress Indicator: Question 8 of 30 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