Fronteras

Pima County health officials are warning residents to remain cautious after three people died Sunday after exposure to temperatures that topped 115 degrees.

A 54-year-old woman died in the mid-afternoon walking in a Tucson neighborhood. Two hikers, including a tourist visiting from Germany died while hiking, Sunday.

Pima County Sheriff Chris Nanos said the heat related deaths this weekend are extreme. "When you lose that many in that short a period of time— three in an hour and a half— that’s pretty critical," he said. "All at the hottest part of the day."

Search and rescue are looking for a fourth person now— another German tourist they believe is lost in Tucson’s Ventana Canyon.

.@PimaSheriff releases this photo of German tourist Search and Rescue looking for in north Tucson mountains pic.twitter.com/2r6bccf7lU

— Michel Marizco (@BorderReporter) June 21, 2016