Latin Tranlation

Qui Vermes Mergent Nin Inferis Frigent

I haven't been around ROFF much for almost two years, but when this
one came my way I knew where to go for an answer...

The story: my uncle and two young cousins (young as in 6 and 7) came
across some guys from the Michigan Fly Fishing Club somewhere in
central PA wearing badges with the above latin phrase. They were
hooting and laughing - saying it meant 'If you fish with a worm, you
burn in hell'.

I tried to translate it and came up with either 'Why drown a worm in
cold water?' or 'How can it be Spring if it's not below freezing?'

I expect that someone here will offer a more convincing translation
than any of those.

Long time no communicado,
Tom G