A 
 Washington doctor warned that he has seen three children complain 
 of headaches caused by the physical stress of relentlessly plowing 
 through the epic 870-page adventure. 
 Call them Hogwarts headaches, named after the wizard school that 
 Harry attends. 
 Dr. Howard Bennett of George Washington University Medical Centre 
 wrote in a letter to this week's New England Journal of Medicine 
 that the three children, ages 8 to 10, experienced a dull headache 
 for two or three days. 
 Each had spent many hours reading "Harry Potter and the 
 Order of the Phoenix." 
 After ruling out other potential causes, Bennett told his patients 
 to give their eyes a rest. But the spell cast by the book was 
 clearly too powerful. 
 "The obvious cure for this malady -- that is, taking a break 
 from reading -- was rejected by two of the patients," Bennett 
 said, adding that the children took acetaminophen instead. 
 In each case, the headache went away only after the patient turned 
 the final page. 
 "Order of the Phoenix," the fifth book in the series, 
 has nearly three times as many pages as "Harry Potter and 
 the Sorcerer's Stone," the first book, and Rowling still 
 plans two more tomes. 
 "If this escalation continues as Rowling concludes the saga, 
 there may be an epidemic of Hogwarts headaches in the years to 
 come," Bennett predicted. 
 (Agencies)