I practice/play a minimum of 3 hours a week. I use light strings and low action on my dreadnaught. It's years since I had problems with my fretting fingers going soft, unless I've just had them soaking in dishwater.

A friend who's been playing guitar, fiddle and mandolin for half a century advised lightly drumming your fingertips on any convenient surface whenever it occurs to you. It becomes a habit. I'm not sure it works, but it can't hurt!