In the world of hybrids, heats are one of the things that can knock someone down for days. It's why the members of BTS take suppressants so they don't hit a stump and be unable to perform for their fans. They're extremely serious about it and are always on top of taking them... that is until Jungkook accidentally lets it slip his mind. In other words, Jungkook forgets to take his suppressant during their tour and now Yoongi has to take care of him and make sure he doesn't suffer through it.