As Derrick laid back on the wooden bench, eyes closed and struggling to relax in the humid room, he failed to notice the changes that befell him. The sauna was indeed designed to promote growth, maturity, and development as advertised. Albeit in a more literal and magical sense. The specially sourced waters used for the steam came from the local Generation Lakes, a natural wonder the hotel was built around that could affect people's ages. Drinking or bathing in the waters could affect a person's age, making them older or younger albeit temporarily. However, it was discovered that the maturity waters had a special property when heated to a steam that could speed up the aging process by actually sweating out the youth out of the body like a toxin. The opposite effect couldn't be achieved by the youthening waters so the sauna was not a popular treatment at the spa by all means. Their typical clientele definitely preferred the anti-aging treatments while the younger crowds preferred to get their age related changes from the Clockwork Water Play Zone or in shots from the hotel bar. Which was a problem for the spa staff as bottled youth essence was becoming a rarity, and the artificial stuff was only a temporary fix. So they devised a method to obtain the sweat from their sauna users, and convince the younger clients to use it. A single session can provide them with a month's supply of natural youth, maybe more if their donors are prone to sweat. The more you sweat, the older you get, after all. And unluckily for Derrick, he could sweat like a pro.
Unbeknownst to him, Derrick was already experiencing the effects of the aging steam as his much desired body hair began to grow in. Dark, curly hair sprouted in the middle of his chest, leading a furry trail up to his collarbone and down his stomach which rapidly seeped outwards to cover his abs with a light layer, for now. It spread even further down to his cock and balls, forming an expansive, dense bush of pubic hair. The hair on his arms and legs thickened and spread to the tips of his knuckles. More hair begun to appear in patches across his face, dense on the chin and around the mouth while more sparse across his cheeks.
Meanwhile, Derrick tossed and turned on the bench, finding it uncomfortable and it made him ache. He failed to notice it was really due to his entire body growing a few inches taller, his legs lengthening, his arms growing, his torso expanding. He finally stopped squirming and laid on his back, which had broadened significantly, leaving his right arm to dangle over the bench when he could once fit his entire body on it. He continued to grow bigger with every breath, as his muscles tensed and bulged to larger proportions. His pecs puffed out and rounded into large, protruding globes and hair continued to swirl around them, trying to hide his puffy nipples. His abs were working hard to be visible under the dense fur that coated them, his waist getting thicker to accommodate the hard, defined muscles.
Derrick couldn't take it any longer. It felt like he'd been trapped in this steam room for hours, it was unbearable. He was super sweaty and hot, the bench was hard and uncomfortable, and even his robe had begun to make him itch like crazy in the humid air. He reached over and dug a hand into the top of his robe where the itch was most irritating. He froze up, his eyes shot open, and he felt his gut drop. There was something inside of his robe, something furry. "What the..." he mumbled as he slowly dragged his hand out from the robe, trembling from the feeling of hair passing and clinging to his fingers and palm. He quickly twisted himself back to a sitting position and looked down. There was a dark mass of curls widespread across his pecs, which were now beefy slabs that jutted out from his chest and stretched open his robe. The hair traveled further down and out of sight into its confines. His eyes glanced up to his arms, they'd grown out from his sleeves and were coated in a similar forest of hair to his pecs. It grew undisturbed across the back of his meatier hands and up to the tips of his knuckles. "No way..." he muttered under his breath, grasping his left hand with his right and rubbing his exposed forearm, feeling the multitude of follicles tug and gather underneath his grip. This had to be a dream of some kind, he thought to himself. The steam had made him fall asleep and he was imagining himself changing, transforming into a hairy beast of some sort.
The heat was beginning to feel unbearable. He was already warm with the robe on, and his abnormal hair growth had pushed him over the edge. With a bit of a struggle, Derrick yanked his arms out of the tight sleeves of his robe and pulled it off, chucking it to the corner of the room. He breathed a sigh of relief, running a hand through the substantial amount of hair that covered his torso, looking even thicker as it was damp and matted with sweat. Speaking of thicker, his waist was no longer slim and slender. It had widened to accommodate the rock-hard abs that were just about visible through his body hair. Derrick also noticed with a raised eyebrow that his cock wasn't left out of this unusual growth spurt, and was still growing as it swelled until it stuck out rock hard and erect. It was accompanied by two heavy balls that drooped low in his sack. He gave his cock a little stroke before deciding against pleasuring himself. Now was clearly not the time, he had to figure out what was happening to him. He had to get a better look at himself. Derrick jumped to his feet, stretched to his new height and yelped in pain as he whacked his head against the ceiling. He ducked slightly and rubbed the new lump on the back of his head. He could definitely stand his full height in the room beforehand. And that pain meant he definitely wasn't dreaming, but how could he have grown almost half a foot in that short amount of time? People didn't just grow tall and super-hairy in minutes right? No, that would be crazy. Maybe there was a hallucinogen in the steam that was giving him really vivid hallucinations. That had to be it, none of this could have been real, he justified to himself.
Stumbling his way over to the mirror, his balance wildly off thanks to his new height and weight gain, Derrick kept his gaze down to his hobbit-like feet until he reached it. Slowly, he raised his head, and stared into his reflection. "FUCKING HELL!!" he yelled, slamming both of his hands to his face in shock, the impact lessened by the prickly beard that covered the lower half. He had a beard! An actual, honest to god beard! It was a quarter inch long on the chin, getting shorter and sparser as it spread out across his cheeks. If it weren't for a thin strip of hairless skin under his bottom lip, his mouth would be lost in the mass of hair that surrounded it. he stared at himself not knowing how to react. He felt scared, astonished, ecstatic, anxious. Slowly a grin appeared from under his beard, stepping back to fully take in his body. If this was a drug trip, he was definitely liking it! He was a broad, strapping, sweaty young man with a pelt of damp hair that stretched almost undisturbed from his head to his toes. He turned around and posed in the mirror, taking in his substantial muscle gains and the fur that covered them. He looked like all the other men in his family; big and bulky, brawny and bearish.
Then Derrick stopped and stared at his face. The men... He didn't look like a teenager anymore. It was pretty obvious just by looking at his body. He'd always looked older than his actual age, but now it was more than that. When he looked at his face, it was no longer rounded and sweet. He'd lost his baby fat, his jawline was sharp and angular while his chin was blocky and square. His brow was heavy and gave him a naturally stern resting face. He used to look like a freshman at college, and now he looked more like he was fresh out of college. Derrick thought back to what Hebe had said. The steam could take years off your life... He wasn't just growing hairy and bigger, he was actually getting older! He stared dumbstruck at himself, now seeing his facial hair slowly creep higher on his cheeks, the gap under his lip was vanishing. And his chest hair had expanded its coverage to his shoulders, curly hair popping up before his eyes. Derrick cried out and stumbled back, falling over onto his perky ass. He thought It was cool to look older but he didn't actually want to be older! He couldn't stay in this room a minute longer, he had to get out.