San Bernardino County was placed under an extreme heat warning by the National Weather Service on Friday at 1:22 a.m. The warning is in effect until Saturday Aug. 23, at 11 p.m.
The NWS Las Vegas NV says to be ready for, “Dangerously hot conditions with temperatures around 105 degrees in Kingman, Golden Valley, Dolan Springs; around 110 in Las Vegas, Pahrump, Barstow, Yucca Valley, Twentynine Palms; around 115 in Laughlin, Bullhead City, Needles, Lake Havasu City; around 120 at Furnace Creek in Death Valley National Park. Expect minimal overnight relief. Major-to-Extreme Heat Risk. In the Owens Valley, temperatures will be around 100 to 105, yielding Moderate Heat Risk.”
“Heat related illnesses increase significantly during extreme heat events,” according to the NWS.
The full list of affected locations includes:
- Death Valley National Park
- Western Mojave Desert
- Eastern Mojave Desert, Including the Mojave National Preserve
- Morongo Basin
- Cadiz Basin
- San Bernardino County-Upper Colorado River Valley
- Northwest Plateau
- Lake Havasu and Fort Mohave
- Northwest Deserts
- Lake Mead National Recreation area
- Owens Valley
- Northeast Clark County
- Western Clark and Southern Nye County
- Las Vegas Valley
- Southern Clark County
- Lincoln County

Emergency alerts in Southern California
For “considerable or catastrophic” hazards, emergency alerts will be sent to all enabled mobile phones in the area. To monitor lesser risk, residents are advised to sign up for county alert systems and to monitor agencies’ social media. How to sign up for alerts in your area:
Staying safe in high temperatures
Safety tips from the Environmental Health and Safety office at UC Irvine:
- Drink water: Drinking plenty of water frequently is vital for those exposed to heat. An individual may produce as much as 2 to 3 gallons of sweat per day. To replenish that fluid you should drink 3 to 4 cups of water every hour.
- Take breaks: Taking breaks in a cool shaded area and allowing time for recovery from the heat during the day are effective ways to avoid heat-related illness.
- Avoid some beverages: Avoid or limit the use of alcohol and caffeine during periods of extreme heat. Both dehydrate the body.
- Stop and rest: If you start to feel symptoms such as nausea, dizziness, weakness or unusual fatigue, rest in a cool shaded area. If symptoms persist or worsen seek immediate medical attention.
- Clothing: Whenever possible, wear clothing that provides protection from the sun but allows airflow to the body. Protect your head and shade your eyes when outdoors.
- Be prepared: When in the heat be sure to pay extra attention to those you’re with and be sure you know how to call for medical attention.
For information about cooling centers operated by Los Angeles, Orange, Riverside and San Bernardino counties, see https://ready.lacounty.gov/heat/, https://ocgov.com/cooling-centers, https://capriverside.org/cool-centers and DPH.