After seasonably mild conditions for most of the week, a round of heat and humidity will settle into the region this weekend. Daytime highs in the low-to-mid 90s are expected starting Saturday and continuing through Tuesday, with heat index values set to approach and top 100 by the afternoon and evening hours. Overnight lows will stay in the low-to-mid 70s, offering little relief. Those with outdoor plans should take precautions, including staying hydrated and taking frequent breaks in shade and air conditioning. Relief will be in sight by Wednesday morning.