During a woman's menstrual cycle, changes in hormone levels affect the rate at which a woman becomes intoxicated. Alcohol metabolism slows down during the premenstrual phase of a woman's cycle (right before she gets her period), which causes more alcohol to enter the bloodstream and the woman to get drunker faster.
A hot tub will intensify the effects of alcohol for several reasons. The alcohol will get into your bloodstream faster as your blood vessels will be dilated (opened more) due to the heat and increased blood pressure. Then the alcohol will circulate in the body faster, making you drunker than normal.