What exactly do you take issue with in the article?
The article is about "emotional fever", defined as "a transient rise in body temperature shown in response to a variety of stressors". Article shows that fish can show this behaviour. On the other hand, the "lack of consciousness" or its existence, is not proven. It is just a hypothesis, based on some "view", expressed in [2].
[1] http://rspb.royalsocietypublishing.org/content/282/1819/2015...