In the case of fire, it totally made more sense for her to go out into below freezing weather in a wet bathing suit than stay in the pool surrounded by water. 
Apparently you're not familiar with St. Paul in wintertime.
Put it another way--find a walk-in freezer. Wearing only a bathing suit, soaked from head to toe, without any other clothing, towel, etc., stand in said freezer for 10-15 minutes. Have a nice fan blowing some soothing air around to simulate wind chill.
There's absolutely NO reason this child needed to be left out in weather like this. As suggested, at least get her a towel and let her sit in a warm vehicle.