A heat advisory is in effect today until 8 this evening, as the heat index is expected to hit 105. These hot temps, combined with high humidity may cause heat illnesses. Make sure to drink plenty of fluids, stay out of the sun and stay in air-conditioned rooms. On that note, the heat advisory has prompted the Hollidaysburg Area School District to send students home early today, as they did yesterday. Senior High will leave at 12:30 PM, Jr. High will leave at 12:40 PM, and Elementary students will leave at 1:30 PM.