LANCASTER – Get ready for hot and humid conditions in our region. A heat advisory has been issued to go in effect tomorrow from 11 a.m. until 8 p.m. Heat index values of up to 104 degrees are expected. Hot temperatures and high humidity may cause heat related illnesses. While late July often brings the highest temperatures of the year for much of the U.S., a heat wave combined with intense sunshine and high humidity can be brutal for those who do not have air conditioning or a means to cool off. Family, friends, and neighbors are encouraged to check on those who may be in heat distress, especially young children, senior citizens, and those who work outside. Stay well hydrated through the period and find air conditioned locations to stay cool. Young children and pets should never be left unattended in vehicles as temperatures inside vehicles can reach lethal temperatures very quickly.