Dehydration
Dehydration
[White Hat and Cueball standing together.] White Hat: Many people are mildly dehydrated. And don't realize it. You should drink at least six glasses of water per day.
[A voice comes from off-panel to the left as Ponytail enters from the left and Black Hat from the right in this frameless panel.] Off-panel voice: No, eight glasses! Ponytail: I heard ten. Black Hat: You need to drink at least five glasses of water per minute.
[Megan is standing to the left holding a book or a thick binder along her side while holding up a finger with the other hand. A question comes from off-panel to the right. Above her a caption is written in a small frame that breaks the top of this panel's frame:] Later: Megan: Okay, I just read through every study I could find to try to figure out whether low-grade dehydration is even a real thing. Off-panel voice: What did you learn?
[Megan looking downwards, has two starbursts a circles and two dots above her head signifying dizziness. Cueball stands to the right as another voice comes from off-panel to the right.] Megan: If you spend all day doing research and forget to eat or drink, you start to feel pretty bad. Off-panel voice: I'll get some water. Megan: But how many glas - Whoa, feeling dizzy. Cueball: Maybe you should just drink straight from the tap.

This comic plays on the idea that there is little to no consensus in the scientific community with regard to the amount of water a person should drink per day. In the first panel White Hat presents Cueball with an innocent and sensible suggestion (although controversial) that people should drink six or more glasses of water per day. In the second panel, more characters join the discussion, an off-panel voice claims the most common misconception of eight glasses a day, a number which is not supported by scientific research. Ponytail again goes two higher with ten highlighting the existence of a wide range of so-called 'optimum' liquid consumption 'rule-of-thumb'. Implied here is the variety of health-related books, articles, blogs or other literature published that self-proclaims an optimum drinking formula.
The first sign of absurdity also arises here in the second panel when Black Hat posits that we need 5 glasses of water every minute. This equates to 7200 glasses of water a day, and using an often cited " standard definition of a glass " being equal to 8 oz (236 ml), Black Hat is suggesting that we should each drink 1.7 cubic meters (1700 liters) of water a day, curing dehydration but also causing water intoxication . This is a typical Black Hat kind of statement that he uses to further emphasize the absurdity of the problem at hand.
Some time later Megan , despite having read through all studies on dehydration (or low-grade dehydration in particular), still has not come to a solid conclusion. She becomes dizzy, admitting that she's been so focused on her work, she has ironically forgotten to eat or drink . Her personal experience with dehydration prompts someone off-panel to get some water, but since she couldn't find any consensus in her research, she asks how many glasses they should bring her. Presumably to avoid the question of "how many glasses" entirely, Cueball finally suggests that she should drink straight from the tap, a (tenuously) sincere suggestion seeing her dehydration and following the good advice to drink when you are thirsty until that state has been absolved. In the title text of 1744: Metabolism , released less than 3 months after this one, Cueball mentions how he starts to feel bad if he refrains from drinking, just like Megan here.
The title text contains a mix-up between two often stated intervals; drinking eight glasses of water per day (which makes no sense, see above) and changing the engine oil every 3000 miles (almost 5000 km) which may be a good rule, but not a necessity. Obviously it's impossible to drink 3000 glasses of water, and changing the oil every eight miles (about 13 km) would make driving a car very impractical.
The subject of this comic has been graphed in 715: Numbers and mentioned in the what if? Soda Planet :
Later, in the what if? Faucet Power , Randall comments on the preference for even numbers in the graph, and writes:
How many glasses is "some water" remains an open question.
Beret Guy and Megan are participants of a thought experiment concerning glasses of water and vacuum in the what if? Glass Half Empty .
And the six glasses of water that this comic began with is also mentioned later in 1853: Once Per Day .
This is a rare example of a normal xkcd comic of few panels manages to use five of the seven major characters who actually interact. It is the first comic where Black Hat has spoken (or directly interacted) with White Hat. Until this comic, they have only appeared together in complicated/large drawings where there is no interaction between the two. The only other time this has happened is in 1881: Drone Training .
[White Hat and Cueball standing together.] White Hat: Many people are mildly dehydrated. And don't realize it. You should drink at least six glasses of water per day.
[A voice comes from off-panel to the left as Ponytail enters from the left and Black Hat from the right in this frameless panel.] Off-panel voice: No, eight glasses! Ponytail: I heard ten. Black Hat: You need to drink at least five glasses of water per minute.
[Megan is standing to the left holding a book or a thick binder along her side while holding up a finger with the other hand. A question comes from off-panel to the right. Above her a caption is written in a small frame that breaks the top of this panel's frame:] Later: Megan: Okay, I just read through every study I could find to try to figure out whether low-grade dehydration is even a real thing. Off-panel voice: What did you learn?
[Megan looking downwards, has two starbursts a circles and two dots above her head signifying dizziness. Cueball stands to the right as another voice comes from off-panel to the right.] Megan: If you spend all day doing research and forget to eat or drink, you start to feel pretty bad. Off-panel voice: I'll get some water. Megan: But how many glas - Whoa, feeling dizzy. Cueball: Maybe you should just drink straight from the tap.
