I use hot glue to secure them in place, and laminating the part where it comes out of the foam with the kraft paper gives a bunch of extra sturdiness. I usually put a blob of glue on the entrance hole and push it in with the wire before it hardens.
Wow that is nasty heat over there. I'm glad this winter is decently cold here in Finland and we have snow too which has become more rare these days. Taking pictures of the frosty trees by my kitchen window since who knows how many times I'll have that anymore.