Not to be confused with, but in correlation with a high fever, a fever-high is the feeling of intoxication which results from an abnormally high body temperature. Symptoms which are associated with a fever-high typically include: hallucinations (both visual and auditory), dizziness, irritability, weakness, confusion, and detachment from or the inability to perceive reality. These symptoms are also known to occur while under the influence of such drugs as psilocybin mushrooms (a.k.a. magic mushrooms) and other hallucinogens, hence the term fever-"high." Some of these symptoms can also be associated with the consumption of alcohol.
Nelson: "Man, I had the craziest fever-high last night. One benefit of being sick I guess.
Mitch: "Yeah bro, that shit is the next best thing to shrooms."