A heat wave can create serious health and planning challenges, and this practical weather safety stay guide focuses on simple actions that help you stay safe during hot conditions.[2] Heat waves are described as periods of excessively hot weather that generally last two or more days, with temperatures compared to historical averages for the region.[2] Heat can be very taxing on the body and can lead to heat-related illnesses or make existing health conditions worse.[5] Everyone can be vulnerable to heat.[5]

Heat wave basics

Use official weather advice early, because you do not have to wait for a heat wave to arrive before protecting yourself.[7] A heat wave can mean different conditions in different places because temperatures are compared with historical averages for the area.[2] Conditions that may be considered a heat wave in Boston would not be considered one in Death Valley.[2] Heat waves may not be the flashiest weather headlines, but they can cause widespread, life-threatening impacts.[2]

Do not treat heat as only an outdoor comfort issue, because heat can affect the body and worsen existing health conditions.[5] Pregnant women, newborns, children, elderly people, and people with chronic illnesses are especially subject to quickly overheating.[5] Never leave vulnerable people in a car.[5] No matter the circumstances, it is important to take heat waves seriously.[6]

Before heat

Prepare before summer heat builds, because official messaging says you do not have to wait for a heat wave to arrive to begin protecting yourself.[7] Review heat safety at work, at home, in your vehicle, and outdoors.[5] Make a simple household plan that covers where people will stay cool, who will check on vulnerable people, and how everyone will follow weather information during extreme heat.[5] Keep the plan practical, because the goal is to reduce exposure, avoid overheating, and respond quickly if heat-related illness develops.[5]

Budget-friendly preparation can be simple: identify the coolest room available, arrange shaded rest areas, and plan errands or outdoor tasks around safer parts of the day when official local advice supports that choice.[5] Keep drinking water accessible where people work, sleep, travel, and spend time outdoors.[5] If you rely on a vehicle during hot weather, include heat safety in that plan because heat safety applies in your vehicle as well as at work, home, and outdoors.[5]

During heat

Take official heat messaging seriously, because heat is described as the number one weather-related killer.[2] Stay alert for heat-related illness, because heat can lead to heat-related illnesses and can make existing health conditions worse.[5] Reduce unnecessary heat exposure when conditions become extreme, especially for people who are more likely to overheat quickly.[5] Check on pregnant women, newborns, children, elderly people, and people with chronic illnesses during hot conditions.[5]

Keep children and vulnerable people out of parked cars, because official heat guidance says never to leave them in a car.[5] Treat a vehicle as a heat-risk setting, not just transportation, because heat safety should be practiced in your vehicle.[5] Build reminders into your routine if children, older adults, or people with chronic illness travel with you, because those groups are especially subject to quickly overheating.[5]

At home

At home, focus on preventing overheating and recognizing when heat is affecting someone’s health.[5] Keep vulnerable people in the coolest practical area available, because pregnant women, newborns, children, elderly people, and people with chronic illnesses are especially subject to quickly overheating.[5] Avoid assuming that being indoors removes heat risk, because heat safety guidance applies at home.[5]

Common mistakes include waiting until the heat wave is already underway, treating heat as less dangerous than dramatic storms, and overlooking people whose health can worsen in heat.[7] Another mistake is planning only for outdoor heat, even though official guidance includes heat safety at work, home, in your vehicle, and outdoors.[5] A further mistake is using one region’s idea of a heat wave as a universal standard, because heat wave conditions are compared with historical averages and can differ by region.[2]

Outside

Outdoor plans should be flexible because heat waves can last for several days and sometimes up to a week.[6] Keep outdoor work, exercise, travel, and errands aligned with official local heat guidance when hot weather is expected.[5] Heat safety applies outdoors, so outdoor plans should include ways to cool down and avoid extended exposure.[5]

Do not wait for symptoms before changing the plan, because official messaging encourages protection before a heat wave arrives.[7] Do not underestimate hot weather because heat waves may seem less dramatic than other weather events.[2] Treat several hot days as a planning problem for the whole household, because a heat wave generally lasts two or more days.[2]

For caregivers

Caregivers should give extra attention to pregnant women, newborns, children, elderly people, and those with chronic illnesses because those groups are especially subject to quickly overheating.[5] Check-ins should cover whether the person is staying cool, avoiding unsafe vehicle exposure, and following the household heat plan.[5] If someone has an existing health condition, heat can make that condition worse.[5]

People caring for children should treat hot cars as a severe hazard because official guidance says never to leave vulnerable people in a car.[5] Safety routines should account for trips, errands, work commutes, and any time a child or vulnerable adult might remain in a vehicle.[5] Heat safety in vehicles belongs in every heat wave plan because official guidance includes vehicles as a heat-safety setting.[5]

Local checks

Local conditions can change, and current weather data may include temperature, condition, wind, humidity, cloud cover, heat index, and UV information.[1] One local weather report listed Sunny conditions and a temperature of 28.8 degrees Celsius at 18:45 on 2026-05-25.[1] That same report listed humidity at 34 and heatindex_c at 28.1.[1] Use local information alongside official heat safety guidance because the heat wave threshold depends on historical averages for the region.[2]

Weather alerts and safety pages can support planning because official weather services include safety resources, local information, and Wireless Emergency Alerts links.[4] Heat safety resources identify heat-related illnesses and vulnerable populations as key concerns.[5] Official social messaging also directs people to prepare for extreme heat before summer heat arrives.[7]

Budget options

A budget-friendly heat wave plan can prioritize no-cost habits: check local weather information, identify vulnerable people, avoid parked-car exposure, and reduce time in heat-risk settings.[5] The most important household upgrades are often procedural rather than expensive: plan cooling breaks, assign check-ins, and keep vehicle routines strict for children and vulnerable adults.[5] If money is limited, focus first on actions that match official advice: prepare before the heat arrives, practice heat safety at home and outdoors, and never leave vulnerable people in a car.[5]

Families can also keep the plan short enough to use during stress, because heat waves can last several days and sometimes up to a week.[6] A simple written plan can list who needs extra attention, where people will cool down, what local weather page will be checked, and how vehicle safety will be handled.[5]

Warnings

Heat can be very taxing on the body and can lead to heat-related illnesses.[5] Heat can also make existing health conditions worse.[5] Everyone can be vulnerable to heat.[5] Heat waves can have deadly consequences when people enter them without proper knowledge of how to keep themselves safe.[6]

Take special care with vulnerable people because pregnant women, newborns, children, elderly people, and those with chronic illnesses can quickly overheat.[5] Never leave them in a car.[5] Do not assume a short heat wave is harmless because heat waves can sometimes last for several days.[6]

Quick checklist

• Check local weather information before heat builds.[1]
• Start protecting yourself before the heat wave arrives.[7]
• Practice heat safety at work, home, in your vehicle, and outdoors.[5]
• Identify pregnant women, newborns, children, elderly people, and people with chronic illnesses who may need extra help.[5]
• Never leave vulnerable people in a car.[5]
• Watch for heat-related illness and worsening health conditions.[5]
• Remember that heat wave thresholds differ by region.[2]
• Treat every heat wave seriously, even when it is short-lived.[6]

For your next step, Check the forecast for your city at PrestoWeather.