FACTS

• Heat Stroke Is a Medical Emergency: Heat stroke occurs when the body’s core temperature rises above 104°F and the cooling system fails. Without immediate intervention it can cause brain damage, organ failure, and death — and it can develop rapidly in workers not yet acclimatized to high temperatures.
• Cold Stress Creeps In Silently: Hypothermia can set in at temperatures well above freezing, particularly when a worker is wet, fatigued, or exposed to wind. A worker shivering uncontrollably may already be in danger — and may not recognize it themselves.
• Shoulder Season Is Deceptive: Spring and fall bring unstable conditions where temperatures can shift dramatically within a single shift, leaving workers overdressed, underprepared, or caught off guard when conditions reverse without warning.
• New Workers Are Most Vulnerable: Workers who have not yet acclimatized to heat are disproportionately at risk during their first few days on the job. Most heat fatalities in the U.S. occur within the first week of exposure to elevated temperatures.
• Frostbite Causes Permanent Damage: Frostbite freezes skin and underlying tissue and in severe cases leads to amputation. Wind chill can lower effective temperatures well below the air temperature reading, accelerating its onset faster than workers expect.

STATS

• Exposure to environmental heat resulted in 48 work-related deaths in the U.S. in 2024 and 7,100 DART cases during the 2023–2024 period, according to the National Safety Council.
• From 2017 to 2022, OSHA investigated 1,054 heat-related workplace injuries, illnesses, and fatalities — including 625 hospitalizations and 211 fatalities.
• Approximately 28,000 U.S. workplace injuries annually are linked to working on hot days, with injury risk rising steeply once the heat index exceeds 90°F, according to 2025 research from George Washington University and Harvard T.H. Chan School of Public Health.
• The three-year average of heat-related worker fatalities in the U.S. has doubled since the early 1990s, according to a National Public Radio and Columbia Journalism Investigations analysis of BLS data.
• From 2003 to 2019, exposure to environmental cold resulted in 31 worker deaths and 2,770 serious injuries and illnesses in the U.S., an average of approximately 163 cold-related incidents per year, according to the Bureau of Labor Statistics.