I've seen this idea, that Bakugou's palms get itchy, a few times in fics and on fandom threads, and I wanted to give it a shot myself. Very loose, and I like the idea that his explosions would reduce the itching, if only because it clears the sweat off his palms. I mean it made sense to me.

Enjoy!

Pt 1: The Nitroglycerin Itch

Bakugou was not typically one to ask for help. Even if he was in pain or in danger, Aizawa had the feeling he'd rather cut his own tongue out. He'd gotten better over the course of his stay in Class 1-A, though. Although, Aizawa was tempted to compare Bakugou's slow progression in that area with Midoriya's own shaky progression in just not breaking a bone. Truly the two were two peas in a very wobbly pod. At least, that was the observation Aizawa had made again and again and again. To his credit, the explosive teenager was always improving with Inui's help as well. Surrounded by peers who constantly encourage him to ask for help and Inui always encouraging the cooperative behavior must have been doing wonders.

That didn't mean he wasn't still stubborn as hell, though.

Stubborn in the sense that his Quirk had a few side-effects—like most—that required some adjustments to daily life and Bakugou just rolled with it how he always did. Stubborn in the sense that he didn't want to waste time trying new habits that might fail to work; and would rather remain doing what he was doing. His Quirk's hinderances were sometimes unavoidable, however. One such hinderance was the heat. It wasn't exactly subtle that Bakugou's callouses were because of the constant blasting. He'd gotten, understandably, accustomed to the heat of the seasons. But just because Bakugou didn't mind the heat himself (not with a Quirk like his), didn't mean the sweating was something he tolerated. He minded very much.

It made him feel disgusting and in need of a shower multiple times in a day. Which in turn meant that he had to make far more of his solution for diluting the nitroglycerin than usual during summer and late spring. Especially during heat waves. Aizawa couldn't help but wonder how many washing machines were destroyed right after his Quirk had manifested.

Aizawa's gaze settled on Bakugou when he returned to class the first really hot day of the season. The wet mop of hair wasn't exactly something he could ignore. He had to have skipped lunch, or very much rushed it, to get to and back from the gym showers in time for class. Bakugou, however, didn't seem to care that the water from his hair was starting to soak his shoulders. He certainly looked like he felt refreshed and back in what could be considered a good mood. At least, by Bakugou standards. It was not fated to last.

Before school was out and they were back in Aizawa's final period, Bakugou was scratching his palms. The heat was the worst it'd been since their initial enrollment and Aizawa heavily suspected that the pent-up sweat was getting uncomfortable. Whether it was itchy or just painful didn't seem that important. What was, was that Bakugou didn't risk setting off his hands right in his own face, or the wall. Or the desk. Or any property of the school.

The next day was worse. The temperatures were reaching heat wave levels and the itching had increased noticeably. By the time classes had ended, no amount of showering had improved Bakugou's mood. It was the third day that Aizawa had finally figured out how to help. He took the time during study period to bring a heavy box over to Bakugo's desk. He let it drop on top, setting his finger on it, and staring Bakugou down.

"Do me a favor," Aizawa says. "And blow this up."

"…What?"

Aizawa shoved it closer. It was clasped shut tight and Bakugou looked up at him quizzically, as did the class. The boy cheekily rested his palm on the top, his hand already smoking. Aizawa's face was unreadable.

"You sure 'bout that?" Bakugou asks.

"The window unlatches if you want to do it now," Aizawa said, turning on his heel.

"This some kinda fuckin' test?" Bakugou asks. Aizawa had already started writing out the first portion of the lesson.

"Just blow it up, Bakugou," he says.

He heard the desk scrape against the floor as Bakugou hefted the box to the window. Likely looking manic. The level of excitement was just a tad concerning. Or, it would be, if Aizawa wasn't acutely aware of just how relieved Bakugou would be to finally have a reason to ignite his sweat. They weren't going to have any scheduled sparring this week until at least tomorrow so he'd had no excuses during school hours so far this week.

"Completely," Aizawa tacks on just as the window is flung open. Bakugou was far from having to be told.

He pushed the window open wide, getting only a brief reprieve of air flow before the heat started to set in again. He held the box up in one smoking palm. The other he raised, palm already sparking, and brought it down onto the lid. The resulting explosion was magnificent. Aizawa was grateful for the window reinforcements that Nezu had refused to skimp on. Days like these really justified it as a purchase. The blast was powerful enough to still rattle the windows—across the entire building by the sound—and the blow back cooled the entire class once the initial heatwave had subsided.

Amongst the sighs of brief content, Aizawa checked his phone, pulling his gaze away as Bakugou looked very pleased with himself. His smile was huge, all teeth, and he still had his hands open to where he had directed the blast outwards over the field. Kirishima was hollering.

Yameme: Was that YOUR class?

MagicEraser: Yes

Aizawa shut the chat and pocketed his phone. He would deal with explaining that later. Bakugou shut the window with a satisfied smirk, looking like he had just entered the best mood he'd been in for the past few days. Aizawa chanced a glance and the boy looked relieved. Aizawa wanted to ask if he felt better; but he refrained. Shame he couldn't thank him for destroying all those old speakers. Hizashi was going to blow a gasket, and his ear drums, but that's what the hoarder got. It was also probably a good thing that Jiro didn't know what was inside the boxes or she would probably have ratted him out. He'd been careful not to grab any sentimental or valuable ones—only the broken ones piled in the "trash" corner—but still.

Bakugou was sitting in class, scratching his palm while he tried to read, and Aizawa was stuck staring at the action. For someone whose Quirk lived in their hands, Aizawa was constantly shocked to see how often Bakugou would harshly treat his hands—particularly the palms. Ashido and Uraraka took care of their hands. They would host "girls nights" where they—and the other girls, and some of the boys—would group together to do hand massages and paint their nails. Yet, Bakugou never seemed to do more than hand stretches.

Aizawa was more focused on care for his eyes, for obvious reasons, so he wasn't sure what else besides massages and preventative stretches the boy could do. But, he had the feeling scratching at his palms wasn't on the list of acceptable treatment in the long term. He was fairly certain that nothing would actually come of it, but it had to be uncomfortable.

Kirishima leaned over Bakugou's desk, passing a small lotion bottle. Bakugou took it in his palm and tossed it backward, hitting Midoriya on the head without even bothering to aim.

"Wh—hey…" Kirishima whined. "I got that for you."

"He needs it more than me," Bakugou says. "I don't need any damn lotion."

"But isn't your skin dry and that's why you're scratching your hands?" Kirishima asks, wriggling his fingers for emphasis.

"That's the same idiot logic for why Sparky over there got you lotion last month."

"….To be fair, my skin does feel better—"

"Oh, fuck off."

"Language," Aizawa reprimands lightly, flipping through his papers. Bakugou clicked his tongue at him, but didn't cuss him out, so he was still in a relatively good mood. "Actually, Bakugou, come here."

Bakugou paused only a second before sighing and coming to the front. A few curious eyes followed him, but they were soon looking away to their own work again, save for Midoriya. The green-haired boy had his eyes glued to Bakugou's back. Aizawa reached under his desk, pulling out another box.

"You want me to destroy evidence again?" Bakugou asks. Aizawa raised a brow at him for the insinuation. To be fair, though, he hadn't given them much to go on the last time; so, it was a fair (if not rather funny and maybe insulting) assumption to come to.

"You're under the impression I impede the law, Bakugou?"

"… No, sir."

"Mhm." Aizawa ignored the entirely unbelievable lie and instead pushed the box towards him. "Just see if you can blow it up."

"Pfft! See if I can? I know I can. Don't underestimate how strong my blasts are!" Bakugou gloated.

He swiped the box off the desk and paused in his motion towards the window once the full weight was lifted off the desk. It was far heavier than the last box, and felt a lot denser, on top of it. He took a moment to really take it in, noting that it wasn't locked or even had a lid, it appeared solid. Bakugou turned to Aizawa suspiciously.

"Got a problem already?" Aizawa asks nonchalantly.

"This some fucking joke?" Bakugou asks.

"Not at all. Blow it up."

Bakugou walked to the window and threw it open. He set the box on the frame, setting a hand on the top to balance it and one on the side. Aizawa turned to watch him. The first explosion was smaller than he'd have expected for a good try, lending him to think it was a test. The following explosion was much larger, rattling the windows. Not a few seconds later, Aizawa felt his phone buzz. He slipped it out of his pocket to check the message the same time Bakugou seemed to realize what the box was.

Yameme: Was that you again?

"The fuck is this?" Bakugou asks, slapping the solid mass of wood and glaring at Aizawa. "Oi, sensei!"

Aizawa quickly replied before looking up.

MagicEraser: Yes

"It's specially treated Baobab wood," Aizawa says, sending off the quick reply before glancing up at Bakugou. "So, blow it up."

"What the fuck even is this bullshit, eh?!" Bakugou shouts.

Aizawa's phone buzzed and he looked back at it.

"DON'T IGNORE ME, SENSEI!"

"B-bakugou, calm down, you're going to get detention," Kaminari whispered.

Bakugou whirled on him with a venomous glare. Aizawa let it happen for a few moments as he read Yamada's response. If nothing else, this was a perfect excuse to ignore Bakugou's question for a moment longer while he tried to think of a way to answer that didn't sound utterly ridiculous.

Yameme: Did Nedzu give you permission for this?

MagicEraser: Bold to assume even Nedzu can stop Bakugou when he really wants to blow something up

"Take it as an exercise," Aizawa says. "Take a break whenever you want, but you're going to blow it up."

"Sensei… are we all going to have tests like this?" Kaminari asks, looking appropriately frightened. Aizawa gave a moment of thought.

"Maybe," Aizawa says with a shrug. He looked back up at Bakugou. "A few rules, though."

"…I'll listen," Bakugou says evenly. He'd be listening regardless or Aizawa was going to force him through a series of detentions, but that was beside the point.

"You're not allowed to burn it. You can attempt to blow it up as many times as you need to until you succeed. You stop your attempts for a break when your hands don't itch anymore and can resume whenever they do."

"Wait a fucking second—"

"You can't soak it to make it weaker. You can't chop it up to make it smaller and therefore easier to break apart in a blast unless that damage is done by previous explosions."

"Is this some fucking way to—"

"No one is allowed to assist you under any circumstance. And you have all year to do it," Aizawa says. He returned his attention to his phone. "Any questions?"

"Is this because of my nitroglycerin? Is it that annoying for you, eh?!"

"Any questions that aren't stupid questions?" Aizawa asks. Bakugou fumed. A small explosion blasted in his palm and the box (what was left of it) and wood block were sent flying out the window.

"I'm adding that you can't do that, either," Aizawa says. Bakugou sent another explosion out the window, complemented by a string of curses. "If it's broken when you go get it, I'm getting a replacement block."

"I have to go get it?! Why can't it stay on the damn ground until we leave?"

"Because I said so and your next period is lunch so," Aizawa pointed to the door. "Hop to it."

Bakugou stormed past, small explosions detonating in his palms. He slammed the door shut behind him. Aizawa ignored the concerned glances of the class and returned to his papers. He had to help figure out the actual 'sting' in this sting operation exercise by next week and he was not letting Bakugou's tantrum for his itching solution deter him from finishing early.

"Aizawa-sensei?"

"Hm."

"Am I going to have to figure out how to destroy a wooden block?" Ashido asks sheepishly. Aizawa looked up at her with a raised brow.

"Do you have an uncomfortable side effect of your Quirk?" he asks.

"Um…. I mean sometimes—"

"Then not entirely, but now I'll see about doing something similar."

"Wh—wait, that wasn't an invite, sensei!"

"Then you shouldn't have asked," Aizawa says. Ashido deflated in her seat, feeling a portion of her soul flying away. Aizawa glanced at her and sighed. "Everyone, make me a list of side effects you're struggling to manage, if any."

It took Bakugou exactly one month to finish destroying the wood block and by then the heat had subsided enough that his itching seemed to decrease considerably as well.

"You can special order one from a shop in Tokyo and have it delivered," Aizawa told him once he'd dropped the few remaining splinters onto his desk. "Did it help with the itching?"

"Yes," Bakugou admitted, seemingly begrudgingly. Aizawa nodded.

"A little loud for a permanent solution, but it'll do for now," he sighed. He pulled a folder from his desk and set it out, flipping it open. "Take your seat, Bakugou."

Bakugou stomped off to his desk, sitting down roughly and crossing his arms. Aizawa held up one of the pages of the folder for the class to see.

"These are the exercises you'll all be doing," he announced. Half the class groaned, with Kaminari's head hitting his desk, and Tokoyami looking incredibly put out. "I based the exercises off the list of side effects you all gave me. Some of you had a better handle on what was wrong than others. Entirely possible you just have very few side effects, however."

Midoriya's hand, unsurprisingly, shot up. Aizawa nodded towards him. "Is this part of the Hero Course typically, sensei? I know we come to UA to learn how to use our Quirks, but I've never heard of a class learning like this."

"Yeah, do other schools do this?" Ashido asks. She sounded genuinely curious rather than hopeful that this would be an argument to use to get out of the impromptu assignment, so Aizawa figured he could cut her some slack.

"No, other schools do not typically do this," Aizawa admitted. "Past general Quirk Counseling, most people just figure out what works for them, so long as it doesn't require any medical intervention. But, UA isn't like other schools. And I've noticed some of you are struggling with certain side effects of your Quirks. So," he grabbed the pages in his hand and started to make rounds around the room to pass them out. "You all have the year to make a habit of these exercises until we can find more permanent solutions. I expect you to give me and Recovery Girl updates so we can figure that out faster."

Once all the pages were handed out, he returned to the front of the room. He let them take time to read each exercise and noted a few reactions. Aoyama seemed to know immediately what to do, and looked rather pleased, so he'd likely already discovered this little trick that Aizawa had suggested. That was a good sign. Todoroki had hardly any side effects given the 'cancel out' effect his Quirk had, so the fact Aizawa had noticed any at all seemed to throw him off a little. Kaminari deflated a little in his chair, alongside Jiro. Hagakure was giggling like a mad woman, given her only suggested exercise was focused on making sure she wasn't giving herself headaches with her light laser attack and what to do if she got one. Midoriya just looked impressed. Aizawa made a mental note to ask him specifically if he had any ideas of his own that could help. With all the writings he had in his notebooks, the boy was bound to be able to figure out something.

"Sensei, what do you do for your Quirk? Does it hurt to use?" Satou asks.

"I only get the migraines and eye strain," Aizawa admits. He shrugged and crossed his arms. "Not a lot to do about it but preventative exercises and eye drops."

"Some of us don't really have an exercise centered around Quirk side effects," Todoroki says.

"Because you already have it managed or you don't have one that's proven itself a problem," Aizawa says. "But, I was determined to give everyone something to do… for fairness."

"Is that why mine boils down to ear plug Support Items?" Jiro asks, waving her page in the air.

"Bakugou also has that listed."

"Already have 'em," Bakugou grumbled, shoving his paper in his notebook.

"You should get Hatsume to make them!" Ashido says excitedly.

"No!" Midoriya and Bakugou both shout. The former rather desperately and the latter rather angrily.

"Maijima is making whatever Items you'll need, you just need to give him specifics, and you'll be adjusting them accordingly as your tenure here progresses," Aizawa says. Uraraka was humming, swaying slightly in her seat.

"Sensei…" she says, raising her hand. She didn't look up to ensure that he'd nodded at her. "One of my listed solutions is gloves?"

"It's easier and cheaper than constantly bolting down every bed you'll use in your life," Aizawa says. "But, bolting is also an option."

Uraraka bit her lip, looking down at the sheet again. She was running the calculations in her head. How much the gloves cost long term, replacement after replacement if necessary, versus how much it would cost to just try tying her bed down without somehow damaging the floor. Aizawa settled in his seat, already waving his lesson plan for the day farewell.

"In the Support Class' lab there are a few pairs of unused design gloves you can try now if you'd like," he offered. Uraraka perked up, smiling.

"Oh! If they don't mind."

"They're not being used. They won't be missed."

Uraraka smiled wider, swaying happily in her seat now, drumming her fingers on the edges of the page. Midoriya was intently studying his own sheet, scratching his temple with his pencil. Aizawa wasn't that surprised. Midoriya's Quirk appeared to have a habit of changing and evolving, sometimes utterly ridiculously. His list was one of the most extensive in the class. In part because he was forced to keep figuring out new side effects of the developing Quirks. It was exhausting enough when Aizawa was trying to figure out all the possible side effects—he had a hard time imagining it from Midoriya's perspective.

It wasn't until class had ended, and the class had filed out with clarifications of their solutions noted on their sheets after an entire class time of discussion, that Midoriya had slid up to his desk. Aizawa leveled his gaze on him, waiting patiently. Midoriya had his notebook open, shifting his weight from foot to foot, looking nervous.

"Yes, Midoriya?"

"Um… well, I had a question regarding one of the solutions?" he began. Aizawa nodded for him to continue. "Um, it's about Fa Jin. One of the ones specified has "exhaustion" with a question mark."

"Do you get exhausted after using it?" Aizawa asks.

"Um… well, I usually use it when I'm sparring or in a fight, so I can't say for sure that's just because I use Fa Jin or not…" Midoriya admits.

"We'll have to experiment, then," Aizawa mumbles. He tried not to smirk at Midoriya's excitement about the prospect. "Anything else?"

"A few suggestions on how to hone Blackwhip?"

"It's based on your emotional state, correct?"

"Yes."

"Then, we'll figure out how to manipulate it. Noticed any adverse side effects to any of these?"

"Um… well," Midoriya laid the notebook down, pointing out his notes to Aizawa. "I get headaches from Blackwhip sometimes when I'm practicing, my muscles feel weird after using Float too long… uh, I'm paranoid a lot, but I'm not sure if that's my Quirk or not. I'm always working on the distribution of strength."

"Try the massaging exercises. They'll help," Aizawa stressed. Midoriya nodded, circling those suggestions specifically.

"Oi, nerd! We're training, get your ass in gear!" Bakugou shouted from the hall. Kirishima's voice followed immediately after.

"C'mon, bro!"

Midoriya smiled, stuffing his things into his bag. "Thank you, sensei! I'll report back later."

"Appreciated," Aizawa nodded. He watched him go and tapped his finger on the desk. Midoriya was, by far, going to be the most interesting one to work out a permanent solution for. If he succeeded at that, at all. At least students like Uraraka and Iida were easy to figure out. Iida knew to cool his legs. Uraraka just needed to cut off contact with at least one finger.

Midoriya had a small family of Quirks all coexisting and that had to been bound to give him some issues eventually. By Kami, Aizawa was determined to figure out ways to improve any aftereffects before the boy graduated and procrastinated that himself.