...Heat Indices of 105 to 110 Degrees Expected Today... The combination of above normal temperatures and high dewpoints will result in Heat Indices of 105 to 110 degrees for all of Deep South Texas and the Rio Grande Valley. Peak temperatures are expected from Noon to 7 pm. Residents with outdoor activities are urged to drink plenty of water, wear light weight and light colored clothing and take frequent breaks from the heat. Children and pets should never be left unattended in 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.