SAN DIEGO – San Diego County officials are warning residents and visitors to watch out for heat exhaustion amid the heat advisory blanketing the area through Friday.

Hikers could still be seen braving the Iron Mountain Trail in Poway Wednesday, where temperatures reached mid-80s.

“As I was driving over I noticed a thermometer creeping upwards and upwards,” Bridgette Doig said.

Thursday and Friday will bring temperatures in the 90s, possibly even reaching triple digits in the valleys.

“Definitely sweat a little more than I normally did and it wasn’t nearly as crowded today,” Jen Jardine said.

Cal Fire says while fire season has become year-round in the state, this week’s weather shouldn’t present peak fire danger, but heat exhaustion and stranded hikers remains a big concern.

“I wish people would pay attention to that aspect, otherwise whether it’s a helicopter or they have to go get you, it’s kind of a problem,” Roger Gedminas said.

Things can quickly turn dangerous so officials say to be cautious, pay attention to posted signs and warnings, and always come prepared.

“I always have sunglasses, hat, sunblock, lots of water, as well as a first aid kit,” Jardine said.

San Diegans are reminded to take extra care for the most vulnerable populations including the elderly, young children and pets.