Maybe this is a usefull tip:

When I have to use (open) my PSK in the outdoors, wind, and/or rain I sit with my back in the wind and take out a waterproof bag (that is in my pocket) and place the PSK-tin in that. When I open the kit and something flyes away, it will fly into the bag and won't be lost.
The bag will also help to keep the contents of the opened tin dry.