Los Angeles Heat Sends 1,200 People to ERs Yearly for Dehydration

Los Angeles hit 101 degrees at Los Angeles International Airport on Wednesday, the fourth triple-digit day this July. By noon, the Santa Monica Pier's rental umbrellas were sold out, and urgent care clinics from Venice to Silver Lake were fielding calls about heat exhaustion.

Dehydration is the city's quiet emergency. Data from the Los Angeles County Department of Public Health shows emergency room visits for dehydration-related conditions rose 18 percent between 2021 and 2025, with more than 1,200 visits each summer. The UCLA Fielding School of Public Health estimates that 40 percent of those cases involve adults over 65, many of whom live inland where the heat lingers past sunset.

The Hydration Math That Actually Works

Dr. Samantha Reeves, a sports nutritionist at the UCLA Health Sports Medicine Center in Westwood, said the standard 64-ounce recommendation is a starting point, not a target. In coastal L.A., where the marine layer can mask heat, people often drink less than they need. In the San Fernando Valley, where temperatures regularly exceed 100 degrees, the body loses up to 1.5 liters of sweat per hour during a moderate hike in Griffith Park.

Her clinic's hydration guidelines for L.A. residents are specific: for every hour spent outdoors in temperatures above 90 degrees, add 12 to 16 ounces of fluid beyond baseline needs. Electrolytes, not just water, become critical after 90 minutes of exertion. The clinic's nutrition staff recommend oral rehydration solutions or coconut water with no added sugar, not sports drinks that contain 20 or more grams of sugar per serving.

At the Erewhon outpost on Sunset Boulevard in Echo Park, a 16-ounce bottle of raw coconut water costs $7.49. A hydration-focused smoothie, the 'Sea Moss Green', runs $17. A cashier said demand for electrolyte products has doubled since June.

Where L.A. Falls Short

Drinking fountains in the city's parks are another story. A 2025 audit by the nonprofit L.A. Waterkeeper found that 32 percent of public drinking fountains in the city's 444 parks were nonfunctional, and 18 percent tested positive for coliform bacteria. In Elysian Park near Dodger Stadium, only two of seven fountains worked as of May. That leaves hikers, joggers, and families relying on bottled water, which, at $2 to $4 per bottle at convenience stores along Sunset Boulevard and Ventura Boulevard, adds up quickly.

The Los Angeles Department of Water and Power launched a pilot program this spring to install 50 hydration stations across high-traffic parks, with a budget of $1.2 million. So far, 12 are operational, including one at the Griffith Observatory trailhead and one at the Venice Beach boardwalk. LADWP spokesperson Carla Mendez said the remaining 38 are scheduled for completion by September.

For those who want to skip the wait, the advice from local dietitians is simple: start hydrating before you feel thirsty. A 2024 study from the University of Southern California's Keck School of Medicine found that by the time a person feels thirsty, they are already 2 percent dehydrated, enough to impair cognitive function and physical performance.

On a 95-degree day in July, that's not a small difference. It's the line between finishing a run from Santa Monica to Will Rogers State Beach and cutting it short at the third lifeguard tower.