...ELEVATED HEAT INDEX VALUES THIS AFTERNOON... Heat index values will reach 105 to 108 degrees in many areas this afternoon. A few locations along the Rio Grande and Coastal Plains could briefly reach heat index values near 110 degrees. It is encouraged to take appropriate precautions to prevent heat related illnesses. Plan strenuous outdoor activities during the early morning or late evening. Drink plenty of water, wear light weight and light colored clothing, and take frequent breaks from the heat. Young children, elderly, and pets should never be left unattended in parked vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.