I am in high school, so the term "Hell Week" is official enough to be written into our handbook. This is not very professional in "real theatre," of course, but in our setting it is a useful name.
Keep in mind that for 2/3 of kids who are under 17 (driving age in NY state), their parents have to pick them up at 11 pm, give them twice the amount of money to pay for lunch and dinner, and do twice as much laundry between costumes, tech clothes, and actual clothing. So for all persons involved, yes, tech week is a week from hell.
I really like tech/hell week, though. Things start to come together, the set actually looks passable, and the show seems fresher than ever with costumes and makeup added.