Considering the climate crisis that is taking place on the planet in recent years, the weather continues to get hotter all throughout the year, especially during the summer months.
With more than 2300 heat-related deaths occurring in the United States in 2024 (compared to only 20 in 2014), the threat to health and life is on the rise.
National Heat Awareness Day is here to improve personal awareness as well as build safety protocols into communities to help protect from the dangerous health issues – to both humans and pets – that can result from hot weather.
National Heat Awareness Day Timeline
Trousseau formally describes “coup de chaleur” in medical literature
French physician Armand Trousseau publishes a detailed account of heat stroke among troops and laborers, helping define it as a specific, life‑threatening condition.
Researchers propose a modern clinical definition of heat stroke
S. Sayers and colleagues publish work outlining core temperature criteria and neurological symptoms, shaping contemporary diagnosis and emergency care for heat stroke.
United States endures a deadly nationwide heat wave
A prolonged summer heat wave kills more than 1,200 people across the United States, prompting closer tracking of heat‑related mortality and the need for formal warning systems.
Robert Steadman develops the Heat Index
U.S. scientist Robert G. Steadman introduces a “temperature‑humidity index” that evolves into the Heat Index, used by the National Weather Service to guide public heat advisories.
Chicago heat wave exposes gaps in heat emergency planning
A severe July heat wave in Chicago kills more than 700 people, especially older and isolated residents, leading to new city heat emergency plans and attention to social vulnerability.
How to Celebrate National Heat Awareness Day
Check out a few of these ideas for getting involved with National Heat Awareness Day:
Stay Informed
The most important thing to do for National Heat Awareness Day is to get educated and better understand the ways to stay healthy in the hotter months.
Record setting temperatures are a threat to everyone but especially elderly people, as well as women who are pregnant or folks who have conditions such as asthma or diabetes.
Read up on health websites, talk to your doctor and maintain healthy practices all summer long, espeically on the hottest days.
Enjoy the Sun Safely
Summer is an important time for getting into the sun and enjoying fun activities. Remember these tips for sun safety:
- Check the weather before going outdoors
- Avoid direct sun exposure and strenuous activities
- Regulate your temperature with light, loose-fitting clothing and a hat to shade your face
- NEVER leave children or pets in the car
Check In on Loved Ones
This is especially true for those who have at-risk neighbors or family members. Stop by or call to find out what kind of assistance they might need ahead of the hotter weather.
This might include arranging for an air conditioner repair person, checking to make sure fans are working, or reminding friends to avoid using ovens, stay out of direct sun, close curtains and window shades, and stay hydrated.
Learn About Climate Trends
Those who want to better understand the background of National Heat Awareness Day can take some time getting more information related to the reasons behind our rising temperatures here on the planet.
Check out some of these important facts according to the US Fifth National Climate Assessment:
- Extreme weather events are becoming more common and more severe
- Climate change may be mitigated by reducing the emissions of heat-trapping gases like carbon dioxide
- The highest year for US emissions was 2007 and cleaner energy has helped this decline since that time
- Progress with wind, solar and battery storage technologies allow continued advances that will hopefully restore the earth to its healthier temps
History of National Heat Awareness Day
Started in 2024 by the US Department of Health and Human Services, this event is meant to act as an opportunity for people all over the country (and the world!) to create safety protocols within their families and communities.
This event is also supported and promoted by the Occupational Health and Safety Administration and the National Weather Service.
Facts About National Heat Awareness Day
Heat Is the Deadliest Weather Hazard in the United States
Across decades of records, extreme heat kills more people in the United States each year than any other kind of weather, including hurricanes, tornadoes, floods, or lightning.
The National Weather Service notes that major heat waves, such as the 1980 central U.S. event that caused more than 1,250 deaths and the 1995 Chicago heat wave with over 700 deaths, illustrate how quickly mortality rises when high temperatures persist for days without relief.
Nighttime Heat Is Rising Faster and Increases Health Risks
Climate assessments show that in many regions of the United States, minimum nighttime temperatures are rising faster than daytime highs.
Hot nights prevent the body from cooling down, which increases strain on the heart and can worsen chronic conditions like cardiovascular and respiratory disease, especially among older adults and people without air conditioning.
The Fifth National Climate Assessment reports that the frequency of warm nights has increased markedly since the mid‑20th century and is projected to continue climbing as the climate warms.
Humidity Makes “Feels Like” Temperatures Much More Dangerous
The National Weather Service’s heat index combines air temperature with relative humidity to estimate how hot it actually feels to the human body.
High humidity slows the evaporation of sweat, which is the body’s main cooling mechanism, so a temperature of 92°F with 65 percent humidity can stress the body like an air temperature near 100°F.
As a result, the same thermometer reading can be relatively safe in dry conditions but hazardous when the air is moist.
Urban Heat Islands Can Be Over 10°F Hotter Than Nearby Areas
Cities tend to run significantly hotter than surrounding rural regions because pavement, dark roofs, and concrete absorb and store heat while trees and vegetation are often sparse.
The U.S. Environmental Protection Agency reports that on a hot summer afternoon, urban air temperatures can be 1 to 7°F higher than nearby rural areas, and urban surfaces like asphalt can exceed rural surface temperatures by as much as 27°F.
These “urban heat islands” particularly endanger residents in neighborhoods with fewer trees and more impervious surfaces.
Structural Racism Shapes Who Dies From Extreme Heat
Research by New York City’s health department found that an estimated 525 New Yorkers die each year from heat-related causes, and that Black residents have about twice the heat-stress death rate of white residents.
The report links these disparities to structural racism, including historical housing discrimination that left many Black communities with fewer trees, less green space, and poorer-quality housing that is harder to cool, as well as unequal access to air conditioning.
Outdoor Workers Face Elevated Heat Illness Risk on the Job
Construction crews, farmworkers, delivery drivers, and other outdoor workers are at higher risk of heat exhaustion and heat stroke because they often perform strenuous tasks in the sun for hours at a time.
Federal occupational health agencies highlight that physical exertion intensifies heat stress, especially when workers are not acclimatized to heat, lack shaded rest breaks, or have limited access to cool drinking water.
These conditions can turn otherwise manageable temperatures into life-threatening exposures.
Extreme Heat Drives Hundreds of Thousands of Medical Visits
Analyses of hospital and emergency department data indicate that spikes in temperature translate quickly into health care demand.
One national study estimated that extreme heat event days in the United States are associated with nearly 235,000 emergency department visits and more than 56,000 hospital admissions each year, for problems ranging from dehydration and heat stroke to heart, kidney, and respiratory complications triggered or worsened by heat.
