I always suggest that shelters be checked for holes since the thin foil outer cover is really all that protects you via reflectivity. Any pinholes in the outer foil can lead to rapid failure of the “shelter” in a real deployment situation and subsequent injury or death to the firefighter inside. I don’t recommend initially opening the shelter to check it, rather one should look for loose grey dust in the clear plastic package and/or other signs that the reflective foil is degrading along the folds. I do recommend however checking closer if you do see any sign whatsoever of degradation by opening up the shelter. Do it as a group exercise in full sunlight as if you can hold it up and see pinholes the shelter is no longer useful for its lifesaving purpose and should be discarded. This is the only real way to learn how to judge how much actual deterioration may exist during future “in the bag” inspections. I teach that any visual deterioration is too much. Would you feel safe jumping from a plane with a small rip your parachute? I wouldn’t
Removing defective shelters from their bags also effectively removes them from service. Don’t leave obviously worn shelters in their bags…they may be mistakenly handed out again.