Author: Sam Killian, MD Educational Pearls:   Headache is a common complaint in the ED. It’s plausible that headaches could be correlated with environmental factors A 2015 study ED visits for headache found that temperature was associated with an increase visits, while higher humidity led to fewer A retrospective study looking over a 10-year period for headache found that there was an increase headache presentations during days with high air pollution   References: Yilmaz M, Gurger M, Atescelik M, Yildiz M, Gurbuz S. Meteorologic parameters and migraine headache: ED study. Am J Emerg Med. 2015 Mar;33(3):409-13. doi: 10.1016/j.ajem.2014.12.056. Epub 2014 Dec 31. PubMed PMID: 25601162. Szyszkowicz M, Stieb DM, Rowe BH. Air pollution and daily ED visits for migraine and headache in Edmonton, Canada. Am J Emerg Med. 2009 May;27(4):391-6. doi: 10.1016/j.ajem.2008.03.013. PubMed PMID: 19555607. Summarized by Will Dewispelaere, MS3 | Edited by Erik Verzemnieks, MD