Extreme heat resources and references for providers


Heat-related illnesses and deaths are preventable. CDPHE aims to equip the state’s providers with the information and resources they need to prepare for and respond to heat-related emergencies so we can keep all Coloradans healthy during extreme heat.

Approximately 1,220 people in the United States die from extreme heat every year. In 2023, the state identified 13 heat-related deaths, 474 emergency department visits, and 51 hospitalizations in Colorado using hospital discharge and death certificate data. 

Extreme heat and health

Extreme heat occurs when summertime temperatures  are much hotter or more humid than average. It can cause heat-related illnesses such as heat exhaustion and heat stroke. A heat stroke is a medical emergency, and rapid recognition and early treatment are essential to reduce morbidity and mortality. Extreme heat is also known to increase secondary adverse outcomes such as cardiovascular (e.g., myocardial infarction, cerebrovascular accident), respiratory (e.g., COPD/asthma exacerbations), and renal (e.g., AKI, electrolyte abnormalities) complications.

At-risk populations

Extreme heat can impact anyone, and it is important to take actions that help the body cool itself to prevent heat-related illness.

Traditionally, people at increased risk of heat-related illness include individuals aged 65 and older, individuals with chronic medical conditions, pregnant people, infants and children, outdoor workers, athletes, and people without access to air conditioning — which may include people experiencing homelessness and low-income households.

CDPHE heat-related illness data

Public health monitoring on heat-related illness occurs from May 1 to Sept. 30. CDPHE has a heat-related illness dashboard that displays Colorado heat-related illness surveillance data. This year, we added near real-time heat-related illness data to the dashboard. This data displays emergency department visits, hospitalizations, and outpatient visits related to heat illness during heat season. Currently, the dashboard is limited to direct heat-related illness visits, with plans to expand to include secondary outcomes (e.g., cardiovascular, respiratory, renal, etc.) in the future.


How providers can prepare for extreme heat

Step 1: 

Screen patients for heat and health risk factors using the Centers for Disease Control and Prevention's CHILL’D-OUT Questionnaire

Step 2: 

Establish a heat action plan for at-risk patients. CDC and Americares provide heat action plan templates. Heat action plans should do the following: 

  • Review steps to stay cool and hydrated, and learn how to recognize heat-related symptoms, including when to seek medical care. 
  • Help patients understand what to do when air quality is poor.
  • Check medications that extreme heat can impact and develop a medication plan for hot days. 

A primary care provider or a specialist may complete heat health action plans, depending on who may better understand a particular underlying medical condition and medications, placing the patient at risk (e.g., managing congestive heart failure on diuretics and beta blockers or dialysis patients).

Step 3: 

Work with patients ahead of time to identify people who could check in on them during extreme heat.

Introducing a “Check on your neighbor” program is helpful to ensure patients in more isolated settings have access to community members who can help with their safety during extreme heat events (e.g., rural settings, older individuals living alone, those with disabilities). Help patients think about whether there are family members, friends, neighbors, or other community members whom they can rely on to help make sure they can get access to cool shelter during hot days, know the warning signs of heat-related illness, and will help recognize them in the patient, and who can be responsible for assisting the patient seek medical attention if necessary.

How providers can respond to extreme heat 

Step 1: 

Understand how to use the National Weather Service and CDC Heat Risk tool and Air Quality index. Teach patients to use these tools daily to assess their risk and follow guidance on staying safe. 

HeatRisk is a health-based heat forecast. It integrates health and temperature data to deliver a seven-day outlook for hot weather. HeatRisk uses a five-level scale to indicate how risky the heat level is in a specific area. Each level uses a color to represent risks from heat exposure.

CategoryRisk of heat-related impacts
Green (0)Little to no risk from expected heat
Yellow (1)


This heat level primarily affects people extremely sensitive to heat, especially outdoors, without effective cooling and adequate hydration.

Orange (2)


This heat level affects most people sensitive to heat, especially those without effective cooling and adequate hydration. Impacts are possible in some health systems and people who are heat-sensitive.

Red (3)


This heat level affects anyone without effective cooling or adequate hydration. It will likely impact some health systems, heat-sensitive industries, and infrastructure.

Magenta (4)


This rare or long-duration extreme heat level with little or no overnight relief affects anyone without effective cooling or adequate hydration. Impacts are likely in most health systems, heat-sensitive industries, and infrastructure.

Providers and patients should also understand the relationship between air quality, heat, and health. The U.S. Environmental Protection Agency developed the air quality index to communicate whether air quality is healthy. The air quality index is nationally available and reflects the contribution of common air pollutants to air quality, such as ozone, particle pollution (or particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For more information, visit the CDC’s How to use the HeatRisk Tool and Air Quality Index webpage.

Step 2: 

Remind patients to use their Heat Action Plan throughout the extreme heat season. Ensure patients know when to call 911 or seek care at the emergency department. Providers should quickly identify and treat heat-related illnesses.

Extreme heat can cause heat-related illnesses such as heat exhaustion and heat stroke. A heat stroke is a medical emergency, and rapid recognition and aggressive early treatment are essential to reduce morbidity and mortality.

Step 3: 

Implementation of Electronic Medical Record (EMR) triggers, if possible, can help streamline heat-related illness care plans.

  • EMR triggers in health care settings may include implementing daily EMR temperature triggers or NWS heat risk triggers (e.g., heat risk category 2 (moderate) or above) to include heat-related illness discharge instructions, suggested discharge paperwork based on discharge diagnosis (e.g., heat exertion, heat stroke, dehydration, acute kidney injury, hyperthermia), and/or EMR triggers to provide patients with heat-related illness resources (e.g., cooling centers, prevention strategies, when to call 911) upon discharge. 
  • 211 is a phone resource that should be shared with patients to assist with finding cooling centers when opened by local jurisdictions, including location, address, and operating hours; we encourage local jurisdictions to update 211 when opening cooling centers. The 211 database can be updated online, or by contacting 211 for assistance in updating if needed. People who may need assistance finding cool spaces include people experiencing homelessness and people who use drugs.
  • Consider providing all patients with discharge instructions for extreme heat when the heat risk category is 3 (major) or 4 (extreme). 

How facilities can prepare for extreme heat

Extreme heat events can cause significant risks to the health and safety of people in various facilities, so facilities need to be well-prepared. Below are key strategies to ensure that facilities can handle extreme heat conditions effectively: 

  • Develop administrative procedures to meet emergency and surge staff capacity needs.
  • Provide staff training on heat-health risk information.
  • Create steps to keep clients, residents, and patients cool and comfortable.
  • Ensure access to emergency cooling options, including air-conditioned rooms, fans, ice water baths, and showers.
  • Identify the need for backup generators during possible power outages.
  • Plan for evacuation if the temperature inside becomes uncomfortable.