Heroes who have moments where they have shown to deviate from their heroic moments to either do no heroic deeds or to do the opposite. These heroes have moments where they "heat up" and act differently than they normally would act. These moments are normally short, and the hero returns to doing good for others.

Examples include:

1. A hero who has despaired and lost hope after losing someone close to them, being betrayed, being defeated or failed, having personal issues or they were being looked down by others. Usually, the hero would become hostile and resistant to do anything optimistic as they would rather give up instead of standing up for who they are. Sometimes, the hero would break into tears and lamenting over their problems. Under these circumstances, the hero would prefer to be alone and away from others. After this moment, the hero would come to get over their depression and go back to helping others (e.g. Bigweld, Mipha, Rosalina, Sadness, Luz Noceda, Gou Kazama, Fievel Mousekewitz, Rose of Purity, Kirby, Shuichi Saihara, Alphonse Elric, Kairi, The movie version of Mario, Olivia, Aang, Shoto Todoroki, Simba, Flik, Pikachu, She-Ra, Tikal the Echidna, Twilight Sparkle, Balto, Quasimodo, Moxy, Despereaux Tilling, Rock Lee, Leonardo from the 2003 TV series, Izuku Midoriya, Master Wu, Thorax, and Ruby Rose). In these circumstances, the heroes could even temporarily lose control and seek revenge. However, they managed to regain their sanity and mercifully spare others' lives for good (e.g. MCU Black Panther, MCU Spider-Man, and Raya). Some heroes can be nihilistic in some cases (e.g. John Coffey and Van Hohenheim).
2. The hero becomes hostile and has moments of being a jerk to others. This may be because they are insecure, persuaded by others with bad influence, being annoyed, unintentionally doing it so or going through a phase in their character. In these moments, the heroes would break out of this mentality and apologize to those they have offended. In other moments, the heroes would learn from their behavior and not repeat it (e.g. Fox McCloud, Edge, Kyoko Kirigiri, Blaze the Cat, Thomas O'Malley, Amity Blight, King Clawthorne, Donald Duck, Squidward Tentacles, Tails, Applejack, Esmeralda, Soichiro Yagami, Anne Boonchuy, Zoey, Kiara, and Hilda).
3. The hero would lose their temper and get angry at others, mostly for good and righteous reasons (which can add to their admirability). It is mainly because of something that irritates them, anyone making mistakes, getting into arguments, being deceived, others being jerks or their loved ones getting harmed. However, the hero managed to calm down instantly/eventually and apologized for their outburst (e.g. Tenzin, Jinora, The reboot version of Mrs. Beakley, Della Duck, Krystal, Queen Anna, Nisa, Sunny Starscout, Ochaco Uraraka, Barbie, Silverstream, Kaito Momota, Elastigirl, Hercules, Princess Tiana, Fa Mulan, Tiff, Roxanne Ritchi, Suki, Elizabeth Liones, Pacha, Princess Jasmine, Princess Allura, Asami Sato, The Meta Runner version of Tari, Mark Evans, Mirabel Madrigal, Carl Fredricksen, Emmet Brickowski, D.J. Drake, Mavis Dracula, Paul Edgecomb, Fluttershy from Equestria Girls, Ultraman Mebius, Shizuka Minamoto, Nemo, Hiccup Horrendous Haddock III, Samurai Jack, Lloyd Garmadon, Horace Nebbercracker, Makoto Niijima, Malthus, Samuel Turfblu, and Ginger), though they sometimes don't apologize if the lash out was well reasoned. (e.g. Umi Matsuzaki, The movie version of Princess Peach, Akari Hoshizaki, and Katsu Umino).
4. The hero would make mistakes which had unintentionally caused problems with others. The reasons for this include mischief, carelessness, and somewhat doing reckless things without consent. They could also be used as a pawn and accidentally give the villain the information or supplies they need to do their evil plan. Despite this, the hero would fix their mistakes and promised not to repeat it again (e.g. Mugman, Sora, Bubbles from Powerpuff Girls Z, Dory, Joy, 9, Pops Maellard, Ali Abdul, Wan, The SMG4 version of Tari, James P. Sullivan, Izzy Moonbow, The Titan, Yoda, Barley Lightfoot, Slippy Toad, Belle, Madoka Kaname, the One Optimus Prime, Hubie, Judy Hopps, The movie version of Luigi, Might Guy, The anime version of Kirby, Asha, and Rapunzel).
5. The hero was exposed to toxins or forces that brought out their darkest qualities or something even worse (Everyone has "darkness" inside them, but Pure Goods don't let it control them). The heroes under these instances were either possessed, corrupted or brainwashed from an external source. However, the heroes managed to recover themselves (e.g. Fluttershy, Courage the Cowardly Dog, SMG0, Buzz Lightyear, Raimiverse Spider-Man, Jack Kline, Yugi Muto, Naruto Uzumaki, Nari, Frodo Baggins, Terrako, Tanjiro Kamado, Callie, Master Fu, Palutena, Kion, Nia Teppelin, Paper Princess Peach, Raine Whispers, Twilight Sparkle from Equestria Girls, Shigeo Kageyama, Glamrock Freddy, Makoto Naegi, and Bruce Banner).
6. The hero could be temporarily allying with the villains for their good intentions, on undercover, pragmatic reasons or being manipulated by them for their own gains. However, the heroes would eventually realize it and rebelled against them for this. (e.g. Ariel, the reboot version of Webby Vanderquack, SpongeBob SquarePants, The Collector, Silver the Hedgehog, The Flash, Zane, Flint Lockwood, Sakura Ogami, Sandbar, Miguel Rivera, Mugman, Fenton Crackshell Cabrera, Plankton, Kovu, and Android 16)
7. The hero can have a mental breakdown or a tantrum, such as anxiety, depression, or worse, losing control of themselves. However, they managed to get over with it (e.g. Melony, All Might, Kenzo Tenma, Po, Eri, Huey Duck, Queen Elsa, the Era of the Wilds incarnation of Princess Zelda, Amy Rose, Princess Peach, Eleven, Nezuko Kamado, Mirio Togata, Freddy Fazbear, and Katelin).
8. The hero who has moments of antagonizing others for any reasons, including for good. However, they later reformed themselves and apologized for their actions, sometimes they don't apologize if it's well-reasoned (e.g. AiAi, Papyrus, Charlotte Emily, Mario, Several incarnations of Link, Anthony Higgs, Vautrin, Lukas, Iroh, Kirby and Meta Knight).

In the worst case, the Pure Good may, entirely by accident, commit an act heinous enough for Moral Event Horizon or even outdo a Pure Evil villain, but it was completely out of their control and isn't corrupting at all, they are extremely likely to be Scapegoats whether or not people thought they were evil.

It is important to note that these heroes are either apologetic after their heating-up moments or they learn from their actions, with the exception of mild or well-reasoned cases which aren't negative at all. After these moments, these heroes also reflect and learn from their actions and make necessary steps towards becoming better individuals for those around them.

This is the opposite to Pure Evils with Cooling-off Periods.

They are considered the brighter counterpart to On & Off Heroes who cannot qualify as Pure Good due to their anti-heroical attributes. However, the thing that gets these ones here is how they are more than willing to pick the side of good and have a moral agency and have no corrupting factors and if they have had any back then they likely have shed their corrupting factors away and redeemed themselves like Redeemed Villains or Wholly Reformed.