ThermaCare Menstrual Pain Therapy HeatWraps send real heat deep into your muscles to relax contractions and relieve period cramps for up to 8 hours. They’re thin and discreet enough to wear under clothing on the go or while relaxing. Provides soothing heat for 8 hours of menstrual ...ThermaCare Menstrual Pain Therapy HeatWraps send real heat deep into your muscles to relax contractions and relieve period cramps for up to 8 hours.