Pet Ice Scarf Summer Scarf Cooling And Heatstroke Prevention.  Soak in water for 5-10 minutes to expand and activate cooling effects.  Soak in ice water for maximum effect.  You can also place (an expanded damp) collar in the fridge or freezer for 10-15 minutes to enhance cooling effects.  As it dries it will naturally shrink over time, just re-soak and it’s ready once more.