This fic was born from my hatred of this time of year and how the wasps can never seem to leave you alone as they fly along in their stupor. So, I decided to hurt Casey with my frustration! Hope you enjoy! :)

Late August was always a war zone when it came to the outdoors. Each shift, 51 had to battle the wasps on calls and as they did drills in front of the fire house. It was at the point in the season where the wasps were getting dopey, anticipating the approaching fall, and this caused many instances of the buzzing creatures to hover and fly right into you instead of avoiding you like they normally did.

Casey waved a hand around his head, shooing away the third wasp in the last half an hour as he set up the ropes for the next drill he was running with 81. With the amount of wasps they were seeing, there had to be a nest somewhere on the roof. He'd make sure to check that out later in the evening when it cooled down and the wasps were less busy.

"Ready Kidd? You're going up against Otis next," Casey said as he grabbed the ropes he had prepared and stepped onto the truck's ladder to the aerial.

"Ready Captain!" She replied as she suited up, pulling her helmet onto her head.

Casey climbed up the steps and started up the aerial when Otis asked, "Come on, Captain. Do we really have to be out here running drills? I'm sweating through my bunker gear here."

Pausing, Casey turned and shot a look at Otis who promptly closed his mouth. Even with the distance between them, Casey's no-nonsense face was hard to miss.

"Right. Sorry, Captain. Ready to go."

Casey nodded and turned, chuckling a little once his face was out of sight. While funny, it really was hot out. Casey was sweating just as much, his back damp as the sun beat heavily on their backs, but drills were important to keep their skills sharp and being uncomfortable was part of the job. If anything, it added an extra element to help hone their skills while working through less than desirable conditions.

81's current drill was to test their speed. Each firefighter was paired with someone and they would each take a turn running the course. The first part was to climb the aerial where they would then repel down from the top of the ladder. Once on the ground, they had to unfasten themselves and run through a small obstacle course Casey had set up. It would make them crawl, jump, and maneuver in different ways, judging how well they could navigate tough terrain. Whether it was a crumbling building, debris from a wreck, or any other possibility from the daily accidents they responded to, they needed to be prepared for anything.

Casey was almost finished securing the top anchor points for the repelling portion when a high pitch buzzing in his right ear caused him to jump. Once again, a wasp had made its annoying presence known. He brushed at it absentmindedly as he focused on securing the last knots. The safety of his team was of most importance. He needed to make sure these ropes would hold as they did their drills.

Just as he stood, preparing to turn around and head back down the aerial ladder, a sharp hot sensation at the back of his neck made him gasp, jerking upright as he instinctively palmed his neck. His hand hit something small and he felt it drop further down his back, trapped somewhere in his gear.

"Damn it," he muttered, tentatively feeling his neck. He winced when his fingers came in contact with a small bump. The wasp had stung him! He was so going to look for that nest now. But first he needed-

His thoughts were cut short when another flair of hot pain rippled across his back, lower this time.

He groaned, his arms flailing to try and dislodge the insect from his bunker gear. His movements only seemed to make the wasp angrier, however, as it began to sting him again and again. With each sting, his back became hotter with the pain, the venom flowing through his skin.

Casey flung his arms out, desperately trying to get his coat off, but each time he moved he got stung.

"You okay up there Captain?" He heard Kidd call from below.

"There's a wasp in my gear!" Casey grunted. His back felt like it was actually on fire now.

Finally, he was able to slip one arm free and slide his coat off, shrugging it off the other arm where it fell to the ground below. The sharp pain of new stings stopped, the intense burning remaining, stopped as Casey assumed the wasp flew away and he finally thought he was in the clear. He took a step back, wanting nothing more than to get off this ladder, but stopped when the world swam around him. He blinked, shaking his head to clear it, but the dizziness only got worse. His back was humming with pain, but the rest of his body felt disconnected, his legs weak as they threatened to buckle beneath him.

"Captain?" He heard someone call, but his brain couldn't process who had said it. Their voice sounded distorted and echoey, like he was at the bottom of a well and they were calling him from above.

He took another step, or tried to at least, but his vision danced with black spots and his right leg crumpled, sending him sprawling.

"Casey!"

His body crashed into the ladder hard. He tried to catch himself, but it was like his body had stopped listening to his commands. His right side hit first, his head catching on the right side of the ladder, and then his body angled down, the steep slope of the aerial propelling his body towards the ground. He was barely aware as he descended head first on his back, each rung sending rippling waves of pain through him. Halfway down the ladder he came to an abrupt stop and a wavering face came into view. Casey could hardly make out who it was. The world was warping around him, those black spots still dancing in his eyes.

"Hang on, Captain. We're going to get you down." Otis.

"I'm getting Kelly!" Someone else yelled, Kidd maybe, and Casey's chest clenched. Severide would help. He'd made it all better. And then the world went dark.

Severide rubbed the bridge of his nose as he chucked his pen onto his desk. He was only halfway through his report for this morning's squad call and he was already over it. He thought about taking a break, maybe smoking a cigar with Casey since it was a nice day and they hadn't had the chance to hang out much over the last couple shifts. Sure, they hung out all the time on their off days, they were dating after all, but it was nice to get some downtime between calls.

"Kelly!" Kidd's voice yelled and Severide swivelled in his chair to see her running into the bunk room. Something was wrong. He was up in a heartbeat, emergency responder training kicking into gear. "What happened?"

"Casey-" she started, but that was enough. Severide was already moving. "He was setting up a drill," she explained as they moved quickly through the firehouse. "He started flailing at the top of the aerial and said something about a wasp. We didn't know what was happening and then he just dropped, started sliding down the ladder."

Severide burst through the doors leading to the apparatus floor and broke out into a full run as he saw Casey's prone form on the ground, Otis hovering above him.

"Casey!" He called, skidding to a stop and kneeling next to his boyfriend. "Kidd, get the jump bag!" She didn't need to be told twice. She turned, running toward the medical cabinet on the apparatus floor.

"I radioed for an ambulance. 61 is on a call so they're sending the nearest unit. They said ten minutes," Otis said, face stricken. "I don't know what's wrong. He doesn't seem to have any injuries."

Severide leaned down, pressing his fingers to Casey's neck as he listened to the blonde breathe.

"Breathing is shallow and rapid, pulse is strong but it's fast."

Kidd came running into the driveway, jump bag in hand.

"You said something about a wasp?" Severide asked as she knelt on Casey's other side.

"Casey said something about a wasp in his gear and he was palming at his back."

"Let's turn him over."

Kidd nodded and grabbed Casey on her side. Together they moved him into recovery position to protect his airway but have full access to his back.

Severide scanned his boyfriend's back, not seeing anything at first, but then he noticed a large welt on his neck.

"Cut his shirt. We need to see what's going on beneath it," Severide said as he gently palmed the sting. It was huge, larger than he'd ever seen from a wasp.

Kidd grabbed the scissors from the kit and cut his shirt in one swift motion.

"Oh my god," she gasped when Casey's back was exposed. His back was a mess of welts, swollen and red. There was almost no welt-free space on his boyfriend's back.

"Shit," Severide cursed, looking to Kidd for help. Casey had to have been stung over 20 times. That couldn't be good.

"That many stings creates a toxic reaction. He's going into severe anaphylactic shock," she said, rifling through the kit.

A noise drew Severide's attention away from her as he swivelled to look at Casey.

Casey's face scrunched and he groaned, his back arching slightly as he moved his legs.

"Hey, no, Case, stay still," Severide said, lowering his face so it was closer to Casey's.

"Sev-?" Casey slurred, eyes cracking open.

"Yeah, it's me Case, I'm here."

"H'rts," Casey whined, squeezing his eyes shut as his body shuddered.

"I know, I'm sorry, but we're going to make you better, okay?"

Casey didn't respond, his body jerking again instead. Without warning, Casey's whole body began to seize, arms and legs jerking as his head rolled back. Severide lunged forward, supporting his boyfriend's head before it hit the ground.

Panic seizing him, he looked to Kidd as she surged forward, jabbing an epipen in Casey's thigh. With paramedic calm, she grabbed the oxygen tank and mask and rushed over to Severide, securing the mask over Casey's face just as the blonde stopped shaking and went still.

Kidd leaned down, grabbing his wrist and counting before she dropped it, placing the stethoscope around her neck in her ears as she listened to Casey's chest.

"Pulse is rapid and I can hear stridor when he breathes. The epipen will help, but he needs to get to the hospital now."

As if on cue, sirens filled the air as the ambulance finally arrived.

"You're going to be okay, Case. Help is here. You hang in there, you hear me?" He whispered to the unconscious blonde, pressing his forehead into Casey's hot one before he stepped back, letting the paramedics do their job.

"He was stung over 20 times by a wasp, passed out, and had a seizure. I gave him one dose of epi and that helped but he's going to need more," Kidd explained as they lifted Casey onto the stretcher.

"We'll take it from here," the female paramedic said as her partner rushed Casey to the back of the ambulance. "We're taking him to med."

"Can I come? I'm his boyfriend," Severide said, glancing frantically at where Casey had disappeared into the ambulance.

"Get in," she said and Severide rushed to the back, pulling the doors shut as he got in.

They rushed through the busy streets of Chicago, sirens blaring, but all Severide could focus on was Casey. The medic, Ian, had hooked him up to the ambulance's oxygen and put an IV in, administering more epinephrine that had Casey breathing a bit easier, but the blonde was still unconscious. His face was pale, breaths fast and shallow, and Severide could see that his heart was still racing from the cardiac monitor.

In a blur they were at the hospital and Severide found himself standing in the waiting room alone, staring at the doors Casey had been rushed through.

He wasn't sure how long he stood there before a hand gently squeezed his shoulder.

"How is he?" Severide turned, his body numb, as his gaze met Kidd's. His eyes roamed behind her and he saw the rest of 51, everyone settling into their seats as they waited to hear their Captain's condition.

"Um," Severide started, shifting his weight to his right leg, his mind trying to find the words. "His breathing got a bit better in the ambulance but he was still unconscious. That was the last I saw of him before they wheeled him away."

He inhaled a shaky breath, clenching his hands into fists as he tried to get his emotions in control.

"He'll be okay," she said softly, bringing him in for a quick hug. "The best doctors in Chicago are treating him.

Severide hugged her tightly, needing the contact. Casey would be alright. He had to be.

An hour later Will walked into the waiting room, a neutral expression on his face.

Severide jumped up, closing the distance between him and Will quickly. "Is he okay?"

"We have him on a few different drips right now. We gave him some more epinephrine and now he's getting antihistamines and cortisone to help with the severe reaction to the stings. We also have him on oxygen, but he's responding nicely to all the treatments. With rest and a week of steroid cream to make sure the stings reduce, he should be fine."

Severide blew out a breath, tipping his head back as he rubbed his hands over his face, tears threatening to spill as everything came crashing down on him. Casey was okay.

"Can I see him?"

Will nodded. "He woke up a few minutes ago and was asking for you. His room is right down the hall, fourth door on the right."

Severide nodded his thanks and rushed down the hall, breath held in his chest as he anxiously waited to see his boyfriend for himself.

His steps faltered for a second as he cleared the door. Casey was on his side, his back toward Severide, fully exposed and slathered in white cream. There were two IV bags hooked up to his arm and an oxygen mask strapped to his face. Despite that the sight of Casey hurt made Severide want to vomit, the fact that Casey's back was already less red and swollen had him breathing a bit easier.

"Case?" He asked gently as he walked around to Casey's front. The blonde stirred and his eyes fluttered open halfway. It was clear he was exhausted, but that didn't stop a huge smile from stretching across his face.

"Sev," He said, voice quiet and a bit hoarse.

Severide pulled a chair right next to the bed and he sat, reaching out and taking Casey's hand in his own. "How are you feeling baby?"

"M'okay. Tired and my back still stings, but it's a lot better."

Severide nodded, searching Casey's face for any hint that he was lying, but the blonde looked to be telling the truth. He was still pale, his eyes puffy with exhaustion, but he didn't seem to be in any discomfort.

"You had us scared, Case. What happened?"

"Stupid wasp. Got caught in my gear and stung me a lot. Think I made him mad."

Severide couldn't help but chuckle at the expression on Casey's face. He seemed to be genuinely pondering the wasp's feelings toward him.

"I'd say. It stung you almost 20 times."

Casey's eyes widened and Severide grabbed his face gently with his other hand, rubbing his thumb gently across Casey's cheek. "But you're okay now. You had a massive allergic reaction, but they've got you on lots of meds. You're going to be fine."

Severide smiled softly as Casey nudged his face into his hand. "Good. Need to kill the nest."

"Oh no you don't! You'll be lucky if I ever even let you outside again."

Casey rolled his eyes and they stayed shut for a moment before he opened them again, clearly struggling against his body's need for rest.

"Sleep Case. I'll be here when you wake up."

Casey nodded and closed his eyes, asleep within seconds. Severide lowered his face to Casey's hand, still intertwined with his own, and kissed it softly before he pulled out his phone and sent Boden a message.

Casey's okay. He'll need rest and steroids for a bit, but will be back to 100% soon.

It only took a moment for the Chief to respond.

Good to hear. All of us are wishing him a speedy recovery. I've taken you off shift, you just take care of Casey.

Severide smiled as he sent a text back.

Thanks Chief. Also, could you get rid of the wasp nest before Casey returns?

Already on it.

Severide felt his chest warm as he put his phone back in his pocket, turning his attention back to his sleeping boyfriend. Everything was going to be alright.