HeatwaveReady

The extreme-heat safety checklist

One printable page: what to do before a heatwave, what to do each day during one, and the two numbers that matter — the mid-90s °F fan cutoff and the NWS heat-index danger bands. Every line is sourced from the NWS, EPA, CDC, OSHA or ENERGY STAR — the same sources as our full heat-safety guide.

or press Ctrl+P (Cmd+P on Mac). It fits on one sheet.

Extreme-heat safety checklist

Source-checked · heatwaveready.com/prepare/heat-safety-checklist/ · Every item cites its federal source

Before the heat arrives

  • Find your nearest air-conditioned fallback: a cooling center, mall or library. The EPA lists these as the standard fallback when home cooling isn't available. (EPA)
  • Stock water, plus an electrolyte drink for anyone who'll be active more than about 2 hours. (OSHA)
  • Plan the thermostat: about 78 °F when home and awake, at least 7 °F higher when away, about 4 °F higher while sleeping. Raising the setpoint 2 °F and running a ceiling fan can cut cooling costs up to 14%. (ENERGY STAR)
  • List who you'll check on: adults 65+, infants and young children, people with chronic conditions, people without AC, athletes and outdoor workers, pregnant people. (CDC)

Every day of a heatwave

  • Check the heat index, not the thermometer — humidity stacks the risk. At 100 °F, 15% humidity feels like 96 °F; 55% humidity feels like 124 °F. (NWS)
  • Windows as a valve: closed and shaded while it's hotter outside than in; open overnight when it's cooler out. (EPA)
  • Drink before you feel thirsty. (OSHA)
  • Check on the at-risk people on your list. (CDC)

The fan rule

  • Room in the mid-90s °F or hotter? Stop relying on fans — the EPA says they will not prevent heat-related illness at those temperatures, and federal guidance warns a fan alone above a heat index of about 99 °F can increase heat stress. Get to air conditioning. (EPA; Excessive Heat Events Guidebook)

Know the danger bands (NWS heat index)

  • 80–90 °F: Caution — fatigue possible with prolonged exposure or activity.
  • 90–103 °F: Extreme Caution — heat stroke, cramps or exhaustion possible.
  • 103–124 °F: Danger — cramps or exhaustion likely, heat stroke possible.
  • 125 °F +: Extreme Danger — heat stroke highly likely.

Not medical advice. Heat killed 529 people in the US in 2024 — more than floods, hurricanes and tornadoes combined (NWS fatality summary). Sources linked in full at heatwaveready.com/prepare/ — NWS heat-index chart, EPA Extreme Heat and Indoor Air Quality, CDC extreme-heat pages, OSHA heat guidance, ENERGY STAR cooling guide.

Use it live, not just on paper

The printed sheet can't read your local conditions — the free tools page can. It runs the NWS's own heat-index formula on your numbers (or your local station's live reading) and tells you honestly whether a fan, an evaporative cooler or only an AC will work today.