Extreme Heat
Extreme Heat occurs when temperatures are significantly higher than normal for an extended period. High temperatures can strain the body and increase the risk of heat-related illness, especially when cooling options are limited.
How This Affects Alameda County
Extreme heat impacts all areas of Alameda County, with higher risk in inland and urban communities where temperatures can rise quickly and remain elevated overnight.
Extreme Heat may:
- Increase risk of heat-related illness
- Strain power systems and increase outages
- Worsen air quality
- Increase demand for medical services
Note: Some neighborhoods may experience higher temperatures due to limited shade, dense development, or reduced access to cooling.
Who Is Most at Risk
- Older adults
- Infants and young children
- People with chronic medical conditions
- People without access to air conditioning
- People who rely on powered medical equipment
- People with disabilities or mobility limitations
- People experiencing homelessness
- Outdoor workers and athletes
Learn more on preparedness considerations and resources for the whole community.
Extreme Heat Safety Tips
Before, During, and After Extreme Heat
- Monitor weather forecasts and heat alerts
- Identify places to cool down, such as air-conditioned buildings or cooling centers
- Drink water regularly, even if you are not thirsty
- Limit outdoor activity, especially during peak heat
- Wear lightweight, light-colored clothing
- Use air conditioning or visit cooling centers when available
- Check on family, neighbors, and others who may need assistance
- Never leave people or pets in parked vehicles
- Plan for pets and ensure they have water and shade
Recognize Heat-Related Illness
Heat Exhaustion
Heat exhaustion is a heat-related illness that can develop after prolonged exposure to high temperatures.
Common signs of heat exhaustion:
- Cool, pale, or clammy skin
- Headache
- Heavy sweating
- Nausea or vomiting
- Weakness or dizziness
Take Action if you notice the above signs:
- Move to a cool place
- Drink water
- Rest
- Use cool cloths or take a cool shower
Note: If symptoms worsen or do not improve, seek medical care.
Heat Stroke
Heat Stroke is a life-threatening emergency where the body can no longer regulate temperature.
Common signs of heat stroke:
- Confusion or altered mental state
- High body temperature
- Hot, red, or dry skin
- Loss of consciousness
- Rapid pulse
Take Action if you notice the above signs:
- Call 9-1-1 immediately
- Move the person to a cooler area
- Use cool cloths, water, or fans to lower body temperature
- Do not give fluids if the person is unconscious
Extreme Heat Alert and Warning (National Weather Service)
Understanding alerts helps you take action early. The National Weather Service provides heat alerts, forecasts, advisories, and warning information.
Excessive Heat Watch – Be Prepared: are issued when conditions are favorable for dangerously hot temperatures. Prepare for extreme heat and monitor updates.
Heat Advisory – Be Aware: are issued when hot conditions are expected that may cause heat-related illness. Take precautions to stay cool and hydrated.
Excessive Heat Warning – Take Action: are issued when dangerous heat conditions are occurring or expected. Take immediate steps to protect yourself and others.
Extreme Heat Resources
211 Alameda County: Dial 2-1-1 for information and referrals to local services, resources, and support in multiple languages during extreme temperatures
Alameda County | Health Care for the Homeless: Resources and support during extreme weather events
Alameda County | Open Cooling Facilities: Find air-conditioned locations open during extreme heat events
American Red Cross | Water Safety and Swimming Guidance: Provides safety tips when cooling off
National Highway Traffic Safety Administration (NHTSA) | Look Before You Lock Campaign: Information on how to prevent heat-related deaths in vehicles
National Integrated Heat Health Information System (NIHHIS) | News & Events: Discover heat and health information, offering forecasts, planning tools, and safety guidance to help you prepare for and respond to extreme heat
National Weather Service | Heat Alerts: Provides heat alerts forecasts, advisories, and warning information
Ready.gov | Extreme Heat: Guidance on preparing for and responding to extreme heat