Impassioned
Passionate Enthusiasm, Passionate, Vehement
noun, な adjective
This fever is violent. This is the feeling you get when you have crazy passionate enthusiasm, aka you are impassioned.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
そのバンドの熱烈なファンが会場をいっぱいにしていた。
The venue was filled with passionate fans of the band.
彼からの熱烈なラブレターに感動して、付き合うことにしたんです。
I was moved by his impassioned love letter, and decided to start dating him.
彼はその作家の作品を熱烈に支持している。
He is a fervent supporter of that author's works.
その女性は、「トーフグの熱烈なファンなんです」と言って、コウイチに熱烈なキスをした。
The woman said, "I'm an ardent fan of Tofugu," and gave Koichi a passionate kiss.