I tend to agree, I fished tournements for years and never saw 20% Kill not even in the Hot Summer Months, I do beleive that fish in a live well can be stressed and their slim coat removed which could cause problems down the road for the fish. I caught a fish once that caused me to beleive this, 75% of his body was covered by a fungus. But even today there are many products that protect the slim coat and add oxygen to the water and as other guys said Ice is always good to use I even use it on my Minnows today.