Room temperature. A steamy bedroom might sound sexy, but it's honestly just sweaty. Caffeine intake. A 2014 study suggests that ingesting caffeine can lead to a higher core body temperature. Hormones. Fluctuations during your period, perimenopause, and menopause often trigger hot flashes. Medications. Many meds have side effects like night sweats, restlessness, and hot flashes. Your body or lifestyle. Some folks just give off more heat. Age, body type, and exercise can also dial up your perspiration.