Stargate SG-1 by Gekko Productions, MGM/UA and others.
Spoilers for eps "1969" and "Fragile Balance"
Jack woke up pissed. Overnight he'd shrunk to half his size. Bad enough he was in pajamas that had been out of style for thirty years, from his point of view, he had to hold them up with one hand as he stood up or they'd have slid off his youthened form.
Grunting, Jack awkwardly stepped over to the sprawled form of Teal'C and kicked the man gently in the face until he woke up.
"Well," Teal'C said, blinking the sleep out of his eyes so he could scan the room. "It seems we have a small visitor."
"Oh, for God's sake, Teal'C." Jack pouted. "You could at least stand up, if not actually roll towards a weapon. I could be a threat, with a bomb strapped to my chest or something."
"In those pajamas, Colonel O'Neill? I think not."
"Hmph. Well, at least you recognize me." Shaking his head, Jack noticed Daniel had made a half-hearted attempt at sitting up. "Hey, egghead. Why didn't you mention this could be a consequence of time travel? I thought we'd just, y'know, boldly walked into the past where all the normal rules of physics still apply. Other than, well, the light bending when we first dropped in."
"Even if that was the case," Sam said sleepily from behind him. "There's no reason it would've singled you out and not touched the rest of us... And - colonel - you're so young
"I could too be affected, but over the same span of years the changes would not be visible." Teal'C touched his forehead. "Perhaps my symbol would be in a slightly different style."
"Yeah, yeah." Jack rolled his eyes. "Freakin' Jaffa longevity. Even if it was just my body adjusting to us being stranded in 1969 I'd be nearly twenty! Right now, I don't feel old enough to shave."
"Really, how much hair could you have had now anyway?" Sam winced, backing down from Jack's glare. "Sorry, half-asleep. I should be more used to this sort of thing by now."
Jack kicked at the sheets in frustration. "We're supposed to be breaking into a secure facility today! What if we have a gunfight and I can't handle the recoil?"
From Earth's atmosphere, the Asgardian scientist Loki monitored the opening of a Stargate which quickly accepted the three energy signatures he'd been tracking as time travelers.
The wave of encoded information left Earth, looped once around the sun and, after being charged by a solar flare, suddenly disappeared from his frame of reference.
"Oh," he cried, doing the alien equivalent of a face-palm. "They took the back way in!"
"Well," he said, walking up to the comatose form of the elder Jack O'Neill, strapped as it was into a monitoring bank. "Looks like I can't reinsert you back into your crew like I wanted to. I could put you in cold storage and unfreeze you when we've caught up to your present, or I could do it now and have a captive lab assistant. Decisions, decisions."