SAN DIEGO — With triple-digit heat indexes becoming more common across California, construction teams in San Diego are turning to technology to keep workers safe and comply with stringent state heat illness prevention laws.

On Thursday, temperatures in downtown San Diego hit the critical range that triggers Cal/OSHA’s workplace safety requirements. At the bustling construction site of the future Hilton hotel on Fifth Avenue and Ash Street, Frank Najera, superintendent for Davis Reed Construction, demonstrated how his crew uses real-time heat monitoring tools.

"We use the app called Heat Index, and it tells you it feels like 82 degrees," Najera said, holding up his phone to show the reading.

Under California law, that reading isn’t just a number — it’s the cue for supervisors to act. Once the heat index reaches 80–82 degrees, employers must provide water, shaded rest areas, and encourage workers to take cool-down breaks.

Najera immediately notified his crews.

"They have to be allowed to. We can't just keep people working," he explained.

The Heat Index app Najera uses is OSHA-endorsed and helps supervisors track temperature thresholds, implement safety measures, and document compliance — a vital feature as state inspectors ramp up unannounced site visits during the summer.

"It's a great tool. Not everyone uses it, but it keeps people alive," Najera emphasized.

Layered Safety Measures Across the Site

Walking through the Hilton project, Najera pointed out shaded rest zones stocked with bottled water, fans, and misting stations. On the building’s 16th floor — where exposure to direct sunlight is intense — temporary shade structures have been installed to reduce heat stress.

"We're shaded. We have a good breeze. The temperature is probably a little lower here, and you'll see bottled water everywhere," he said.

If temperatures climb to 95 degrees or higher, California’s “high-heat” protocol kicks in, requiring supervisors to actively monitor workers for signs of heat exhaustion or heat stroke and to conduct regular check-ins.

Rules That Go Beyond Construction Sites

California’s heat illness prevention standards — some of the strongest in the nation — apply not only to construction but also to agriculture, delivery services, warehouse work, and outdoor athletics.

Keenan Washington, a delivery driver navigating San Diego’s sweltering streets, shared his personal survival tactics:

"I just stay hydrated, make sure I drink a bunch of water. I stay in the car if I can and keep the AC on."

Devin Riley, a freshman football player at Mesa College, said discipline in heat is part of his training mindset:

"Practicing in this heat is getting your mind right. What I do is pour water down my back. Hydrate with electrolytes every day."

Statewide Effort to Prevent Heat Illness

The rules are enforced under Cal/OSHA’s Heat Illness Prevention special emphasis program, which blends strict enforcement with multilingual training and outreach. Davis Reed Construction is part of the agency’s voluntary Heat Illness Prevention Network, designed to share resources and encourage proactive safety planning.

Importantly, California’s worker protections apply regardless of immigration status. Workers or employers with questions about compliance can call 833-579-0927 to speak to a bilingual Cal/OSHA representative, or file confidential complaints about unsafe conditions with local district offices.

As extreme heat events become more frequent due to climate change, safety officials say these laws and tools are critical. Najera believes technology, coupled with vigilance, will remain a cornerstone of keeping crews safe.

"When the temperature spikes, you can’t just push through it. The app keeps us alert, and the rules keep us accountable. It’s about going home healthy at the end of the day," he said.

Originally reported by Abbie Black in CBS 8 News.