'Superstore' Sneak Peek: Uh Oh! Glenn Has a Health Scare During Cloud 9 Staff Meeting (Exclusive)

ET exclusively debuts a first look from Thursday's episode.

Uh oh, someone isn't looking so hot.

On Thursday's episode of Superstore, titled "Self-Care," former Cloud 9 manager Glenn (Mark McKinney) experiences a health scare that prompts one of his fellow employees to take action, and only ET has the exclusive sneak peek at the opening scene.

During a staff meeting led by Amy (America Ferrera) and Dina (Lauren Fox), Glenn looks a little worse for wear as he tries to persuade himself -- and everyone around him -- that he's actually not ill. (Spoiler alert: He very much is.)

In ET's first look, it becomes increasingly difficult for Glenn to concentrate or stay upright the longer the meeting goes on, as Amy and Dina point out everything that's not going right at Cloud 9 before a mandatory health and safety check set for that week.

"Glenn, you're our emergency captain so --," Amy begins to ask Glenn, before he makes a worrisome noise that she mistakes for annoyance. "Glenn, come on, you too?!" 

"No, I just have a really bad headache. You know, the kind where your body tingles all over and your lungs shrink?" Glenn says, his skin getting a little blotchy as he then decides to get up and try to hydrate. It doesn't go so well, as he nearly trips over.

"Why don't you sit down and somebody else can get you some water," Amy says, but Glenn, stubborn as he is, continues to try to make his way to the water fountain -- to no avail. At one point, mistaking Jonah's (Ben Feldman) cell phone for a cup. 

When Amy attempts to get him to sit back down, Glenn fights back in a very Glenn way. But then, things take a very dark turn. Watch ET's exclusive sneak peek above to see what happens next.

Superstore airs Thursdays at 8 p.m. ET/PT on NBC.

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