Hot weather increased the risk of severe headaches. This has been studied by neurology that more than 7000 people diagnosed with headache in a US hospital over a period of seven years. During the research, they compared air temperature and atmospheric conditions in three days leading up to teach headache and found that hotter weather and lower air pressure were associated with more headache. At the end of the study, the conclusion is that the headache risk increased by 7.5 percent with each 5 degrees Celsius increase in temperature. so..be careful everyone.