#thermoregulation

When temperatures rise, sleep often suffers. Hot nights can make it harder to fall asleep, increase waking during the night and leave people feeling less rested the next day. One reason is thermoregulation, the body's ability to keep its internal temperature within a safe range. Sleep is closely linked to body temperature: To fall asleep and stay asleep, the body usually needs to lose some heat. Hot bedrooms make that harder.

Peter Parker & Tony Stark

Summary:

Peter can’t thermoregulate. Now that is usually not a problem, even it’s the middle of winter like now. Unfortunately, Peter’s heater broke.

Great.

Will Tony save him in time? Will it hurt their growing relationship or will it make them stronger?

A/N: Check out my acc on ao3 Eidrif!

Peter didn’t know what was wrong until it was too late.

It was January and even though Peter knew by this time he can’t thermoregulate, he still went on patrol.

Because when the snow is knee-deep people will need help even more. And it was fine anyways.

The suit that Tony build for him, did not only include his very own AI that would surely alert him if something was wrong, but also an often used heater that Tony nicely demonstrated for him when the vulture dropped him in waters, that were nothing in cold compared to Peter’s freezing hands right now.

He shot a web out of his self-made devices and with that, left the guy who was in the act of trying to rob a sandwich shop, glued to a wall.

After a quick confirmation with the shopkeeper, the cops were called and spidey swung away.

Peter stopped at a snowy roof, taking a short break before jumping back in action.

He rubbed his suit-covered hands together and exhaled on them, unfortunately the motion was more for comfort since the suit also covered his mouth.

“Peter, it seems like your suits heater is having some trouble activating. Your temperature is dropping.”

Well. That wasn’t too good.

But as long as Peter didn’t noticed any drastic symptoms, he’d be fine.

“Alright thanks for informing me.” Peter deflected, “Get me into the police radio again Karen?”

“Of course Peter” the AI didn’t push further and patched him through the radio, but her answer seemed clipped.

The kid quickly started swinging to keep a man from attacking a woman in an alley.

Luckily Karen immediately identified the hidden knife behind his back—the fight had been nothing.

But when Peter was about to shoot a web to restrain his arms to his body, no familiar “thwip!” And he had to press twice so the web would finally do its job.

“That’s weird” he audibly muttered before climbing a small house and sitting on the roofs edge.

He inspected his web shooters and came to a quick conclusion. They had lightly frosted and prevented the finger of Peter to properly activate the shooting of the webs.

“Karen can you… maybe unfreeze the buttons?” But all he got was a slightly more robotic voice than usual repeating: “Heater unit-protocol freezing spider-baby unresponsive.”

If Peter wasn’t so worried right now, he might’ve scoffed or laughed at the ridiculous protocol name that Tony made, but he furrowed his brow and made a decision.

“Maybe I should return to the tower for today”, Peter murmured and quickly rubbed his web shooters back to the point of them working.

He swung away—really feeling the cold claim his entire body now.

But mid swing he’s started shivering. The web he was swinging on, shook and Peter could only throw himself on a construction crane in the last second.

He wobbled before sitting down and activating his sticky power. Suddenly, The boy was startled by Karen speaking up again.

“Last attempt at patching error code to Boss. Initiating shut down to preserve Energy.”

And with that she was quiet.

But Peter was getting tired anyways. He didn’t question it and he didn’t need to.

He just needed to lie down for a sec. And with that thought, the kids eyes fell shut.

On a snowy crane in the middle of queens.

~~~~~~~

“Dum-E! Hey get your hands off that!” Tony scolded the robot back at the stark tower in his lab.

The saddened robot let down his pincers while backing clicking sounds.

Tony just scoffed and wanted to turn back to the project he was currently tinkering on, when he was interrupted.

“Boss it seems like Pete’s AI has shut down in necessity.”

Tony immediately perked up at that.

“What why?” FRIDAY tell me more.”

“I just got an error code patched through by the AI. Peters heater malfunctioned and Karen shut herself down in order to preserve more Energy.”

As soon as FRIDAY finished talking, Tony activated the nanotechnology suit and flew out of a window.

He was panicking. The kid couldn’t Thermoregulate. That was exactly why he built the heater in the first place.

And it was not supposed to malfunction.

“Can’t this thing fly faster” He yelled while tracking the last position of his kid.

His repulsors were glowing brighter as he accelerated. Finally he saw the silhouette of the little kid.

Tony didn’t land so much as crash onto the crane.

“Peter!” His voice cracked through the helmet comms even though there was no one to hear it but himself. The kid was slumped against the metal, half-buried in snow, too still. Way too still.

For a split second, Tony froze.

Then he moved.

The nanotech peeled back from his hands as he dropped to his knees, grabbing Peter by the shoulders. The suit was cold—too cold—and stiff under his grip.

“Hey, hey, kid, this is not funny. You don’t get to nap on industrial equipment. That’s, like, rule one of things I definitely told you.”

No response.

Tony’s chest tightened. He pressed two fingers against Peter’s neck. There—faint, but there. Slow.

“Okay. Okay, you’re good. You’re good,” he muttered, more for himself than for Peter.

The mask reformed just enough for a scan. Readouts flickered across his HUD, each one worse than the last.

“Severe hypothermia,” FRIDAY supplied, calm and clinical in his ear. “Core temperature critically low.”

“Yeah, I can see that, Fri.”

Tony swallowed hard, then carefully—far more carefully than anyone would ever believe he could be—scooped Peter up into his arms. The kid felt wrong. Light. Limp.

“Hang on, kid. I got you.”

The suit sealed around them both, generating as much heat as it could without shocking Peter’s system. Tony didn’t wait another second. He launched.

The flight back felt too long. It was only minutes, but every second dragged, stretched thin by the sound of Peter’s uneven breathing over the suit’s sensors.

“Come on, kid. Stay with me. You still owe me, like, twelve homework assignments you promised you’d finish. And I am not explaining this to May.”

No answer.

Tony pushed the suit harder.

The tower came into view and he didn’t bother with a clean landing this time either. He blasted straight through the open platform and into the med bay.

“FRIDAY, prep everything. Hypothermia protocol, now.”

“Already in progress, Boss.”

The med table slid into position as Tony laid Peter down, hands hovering for just a moment like he didn’t want to let go.

Then reality snapped back in.

“Alright, let’s fix you up.”

Mechanical arms descended, carefully cutting away sections of the suit. Tony worked alongside them, faster than usual but precise, peeling back layers to get to Peter.

The kid’s skin was pale. Lips tinged blue.

Tony’s jaw clenched.

“Easy, easy…” he murmured, even though Peter couldn’t hear him. Warm blankets. Controlled heat. IV lines. Oxygen.

“Core temperature rising slowly,” FRIDAY reported.

“Not fast enough.”

He stayed right there, one hand hovering near Peter’s shoulder, like he needed the contact but didn’t quite trust himself not to mess something up.

“Kid, you are in so much trouble,” Tony said quietly. “You don’t get to scare me like that. That’s my thing.”

Peter didn’t stir.

Tony exhaled shakily, dragging a hand down his face before resting it briefly against Peter’s hair, careful, almost hesitant.

“…just—yeah. Just wake up, okay?”

The machines kept beeping. The warmth slowly returned.

And Tony didn’t leave his side for a second.

Time passed in slow, careful increments.

The storm outside softened to a quiet fall, the kind that blanketed the city instead of burying it. Inside the med bay, everything was warm, steady, controlled.

Peter stirred.

It was small at first. A twitch of his fingers under the blankets, a faint shift of his head. Then a quiet, rough inhale that didn’t sound quite right but was stronger than before.

Tony noticed immediately.

He straightened in his chair, which had very much not been there earlier but definitely was now, dragged close enough to the bed that his knee pressed against it.

“Hey,” he said, voice low but alert. “Easy. Don’t go doing any dramatic wake-up scenes. We’re keeping this boring.”

Peter’s eyes fluttered open, unfocused at first. The ceiling lights were too bright. Everything felt… heavy. Warm, but heavy.

“…Mr. Stark?” His voice came out hoarse, barely there.

Tony let out a breath he’d been holding for what felt like hours.

“Yeah. Yeah, I’m here.”

Peter blinked slowly, trying to piece things together. Snow. Patrol. The crane.

“Oh.” A pause. “…I messed up.”

Tony huffed softly, but there was no bite in it.

“Wow. Look at that. Near-death experience and we still get the world’s fastest self-diagnosis.”

Peter gave the smallest, tired huff of a laugh, then winced a little at the effort.

“Sorry,” he mumbled. “I thought the heater would— I didn’t think it would just… stop.”

Tony leaned forward, elbows on his knees, hands clasped tight for a second before he forced them to relax.

“Yeah, well, it wasn’t supposed to,” he said. Then, quieter, “That’s on me.”

Peter frowned slightly. “No, it’s not. I should’ve come back when Karen said—”

“Peter.”

That stopped him.

Tony rarely used that tone. Not loud. Not sharp. Just… firm.

“I built the suit,” Tony continued, calmer now but no less serious. “I’m the one who put you out there with something that could fail. So yeah, I’m in that equation.”

Peter looked down at the blanket, fingers fidgeting weakly with the edge.

“…still my fault too.”

Tony exhaled through his nose, then reached out, very briefly pressing a hand against the side of Peter’s head, brushing back messy curls before pulling away like it hadn’t happened.

“Kid, you almost froze to death on a crane,” he said quietly. “I got a shutdown message from your AI and no signal after that. Do you have any idea what that does to a person?”

Peter glanced up, a bit startled by that.

Tony shook his head, a humorless half-smile tugging at his mouth.

“Don’t answer that. It’s rhetorical. The answer is ‘a lot.’”

Silence settled for a moment.

Then Tony leaned back slightly, looking at him properly.

“I need you to promise me something.”

Peter tensed a little at that, but nodded. “…okay.”

“If something’s wrong like that again—gear, suit, you, anything—you stop.” Tony held his gaze. “I don’t care if it’s the middle of a patrol, I don’t care if you think you can handle it, I don’t care if it’s ‘just one more thing.’ You stop and you come back. No arguing, no pushing through.”

Peter hesitated.

Not long. Just enough to show he was thinking about it.

“…what if someone needs help?” he asked quietly.

Tony didn’t snap. Didn’t deflect.

“They will,” he said simply. “There’s always going to be someone who needs help. But you can’t help anyone if you’re not there to do it.”

Peter swallowed.

“…yeah.”

Tony tilted his head slightly. “That didn’t sound like a promise.”

Peter huffed faintly, then looked back at him, more serious this time.

“I promise.”

Tony watched him for a second longer, like he was checking for cracks in that answer.

Then he nodded once.

“Good.”

Another pause, softer this time.

“…you really scared me,” Tony admitted, almost under his breath.

Peter’s expression shifted, guilt flashing across his face.

“I’m sorry.”

“Yeah,” Tony said, but there was no heat in it now. Just relief. “Don’t make it a habit.”

Peter gave a small, tired smile.

“I’ll try.”

“Not try,” Tony corrected lightly, leaning back in his chair again. “Do. I am way too young for this level of stress.”

Peter let out a quiet laugh, eyes already starting to drift shut again, this time from exhaustion instead of cold.

“…you’re old,” he murmured.

Tony snorted.

“Go to sleep, Underoos.”

And this time, when Peter’s eyes closed, Tony didn’t panic.

Let's begin with the wood frog, found across N. America all the way up to Alaska. It's the only frog known to range north of the Arctic Circle, & it's not easy being a frog when it gets that cold (just ask Kermit, who spent many a chilly day in the Siberian gulag). When winter hits, the wood frog literally freezes solid. Its heart stops beating, lungs don't breathe, & ice forms inside its body. Yet despite this, somehow it doesn't die. How come? Because the frog floods its cells with glucose, which acts like antifreeze. The sugar prevents ice crystals from shredding their cells. When it shuts down its organs, it preserves energy. When spring warmth returns, the ice melts, the heart & lungs restart, & it hops away like nothing happened. It can survive being frozen at 19°F (-7°C) for weeks.

The next extremophile (any organism capable of surviving extreme conditions) is the painted turtle, the breathless winter survivor that lives in N. America. It's N. America's most widespread turtle species. Come winter, they bury themselves under frozen ponds, sealed off from oxygen. Most animals would suffocate. How do they do this? They switch to anaerobic metabolism (living without oxygen). This normally creates lactic acid, which would poison them. But their shells & bones release carbonate minerals that neutralize the acid (they act like buffers or antacid tablets for the blood). They can survive months like this until the ice melts. Imagine holding your breath all winter while your skeleton keeps your blood from turning sour—that's what they do.

The common poorwill is the North American bird that can switch itself off, literally. It takes a route no bird is known to take. Most birds will migrate when their food is no longer available in the region. Not the poorwill. Instead, it tucks itself into rocks & enters torpor, a deep sleep where body temperature. & metabolism drops dramatically. Its body cools to near the surrounding temperature. Its heart rate & breathing slow to almost nothing, & it can stay this way for weeks or months, surviving cold & food scarcity.

The Saharan silver ant is the next extremophile. These ants live in & on the Saharan desert. They literally walk on fire. In the day, the desert sand can reach 158°F (70°C), a temperature that would kill most insects instantly. How do they survive? Well, they have very long legs that lift their bodies above the scorching sand. They track the sun & run back by the shortest route, & their silvery hairs, shaped like tiny triangular prisms, reflect sunlight & help radiate heat away from their bodies, cooling them by several degrees. That's enough to matter when the line between life & death is razor-thin. They dash out for 10 minutes to scavenge any animals that succumbed to the scorching heat, but their window outdoors is narrow. Stay out too long, & they join the next meal.

We've got the elephant hawk moth, found in Europe & Asia, that can actually see colors in the dark. This helps it find flowers at night feeding through a long proboscis. To do this, it must first identify the right flower, hold itself steady & navigate a world with barely any light. Its eyes contain super-sensitive photoreceptors that detect color even when light is almost gone. How about the Mariana snailfish, the deepest ocean dweller? It lives in the Mariana Trenches, 5 mi (27,200 ft (8,300 m)) deep. That's deeper than Mount Everest flipped over. This fish lives under pressures 1,000x the pressure at sea level. That's enough pressure to crush steel, or like having a stack of 50 cars pressing down on every sq. in. of your body. Instead of resisting pressure, it lets it equalize. Its body is soft & flexible, with no air spaces to crush. It also has special molecules called TMAO (trimethylamine N-oxide) that stabilize proteins under pressure. Its body fluids match the surrounding pressure, like a diver adjusting ear pressure underwater.

The most extreme animal known to science is the indestructible microscopic animal, the tardigrade, also known as the "water bear" for good reason. They look like tiny, lumbering bears: a plump body, 4 pairs of stubby legs, a snout for a mouth, & clawed feet. They are tiny, about 0.02 in. (5 mm) & are found worldwide. They live in moss, soil, freshwater & marine sediments. Active tardigrades need water, but when conditions turn bad, they enter a state called "tun," curling up & shutting down almost all life processes. They lose 99% of their water, becoming like dust. In this state, they survive cold (down to -328°F/-200°C). They can survive heat up to 300°F (150°C) & survive in the vacuum of space & radiation & can go decades without water.

We did this today in the heat wave and our house heated up by about 4-5°F (about 2-3°C) in most of the downstairs, with the upstairs and two south-facing rooms (that could be compartmentalized by shutting doors) heating up a bit more.

We stayed in the cool part of the house (which was still a whopping 15°F (8°C) cooler than outdoors, took cold showers, then turned the AC on in the evening, when the temp was falling rapidly from the high and the sun was no longer hitting the house.

How and why does this approach help?

AC works more efficiently the cooler it is outside, and less so the hotter it is outside, so by avoiding the hottest parts of the day, the total cooling costs are reduced.

Electricity demand in heat waves is highest when temperatures are hottest. By avoiding use then, you help reduce peak demand. Peak demand often uses dirtier, inefficient, and more expensive energy sources because businesses prefer to employ cheaper sources first, and renewable sources like solar and wind are in use most of the time they are available because they don't use fuel.

Electricity generationfrom fuel burning generates more ground-level ozone during hotter times, so you help to reduce ground-level ozone.

You reduce the chance of overwhelming the power grid and causing rolling brownouts or blackouts. This pretty much only happens during peak demand.

AC works by pumping heat out of your home, which heats up the outdoors. This effect can be significant in dense urban areas. By avoiding using AC in the hottest hours, you keep the peak temperatures lower, which not only makes the outdoors safer and more pleasant, but reduces costs and electric usage for others still using AC.

By making your home's temperature track the outdoor temp, you avoid extreme heat/cold shock when going in and out of doors. For example a typical high/low in a heat wave is around 95/75°F or 35/24°C. If your AC is kept constant at 70°F/21°C, the difference will be modest at night, but during the peak heat, coming in from outdoors to this temperature will be a huge shock and will likely feel physically uncomfortable to most people.

Allowing your indoor temp to creep up can help with heat acclimation, which can help you to be both safer and more comfortable when you are either outdoors or indoors in a non-air-conditioned space. Remember, power outages are common in heatwaves (both due to grids being overwhelmed, and severe thunderstorms), and if you are dependent on AC you might end up without AC anyway, and you will be better off in an outage if you have allowed your body to acclimate somewhat.

By avoiding AC you can innovate other efficiency measures, like air-sealing your home, using shades or better yet indoor awnings to block out sun, opening your basement door or vents if you have them to draw up cool air from the basement, or planting trees to shade out south- and west-facing windows.

It's a win-win, because it saves you a small amount of money, and saves society even more.

You can ease into this technique, without necessarily going all-in the way we do. For example, around noon, inch the thermostat up 1 degree. Then at 2pm, another 1 degree, and so on until about 5pm. Then inch it down around 8pm and so on until it's cool enough for bedtime.