Dangerous heat remains a concern across the Southwest, where temperatures may exceed 120 degrees in the hottest desert locations. National Weather Service guidance also indicates that unusually hot conditions could expand across parts of the West and south-central United States during the first half of August.
A heat warning is not only a forecast for an uncomfortable afternoon. Prolonged high temperatures, warm overnight lows and humidity can prevent the body from cooling properly and increase the risk of heat exhaustion or heat stroke.
Families should check their local National Weather Service office because alert criteria differ between climates. A temperature that is routine in Phoenix may create an unusual health risk in a cooler region where fewer homes have air conditioning.
What Is an Extreme Heat Warning?
An Extreme Heat Warning means dangerous heat is expected or already occurring with a high level of forecast confidence. The National Weather Service can issue a watch earlier, when confidence is lower, and upgrade it as the event becomes more certain.
A Heat Advisory generally represents a less severe event, but it can still lead to illness. Local offices choose thresholds based on the area’s climate, expected duration, overnight temperatures and potential effect on the population.
Residents should read the complete alert rather than focusing only on its name. The message will identify affected communities, expected temperatures, timing and specific precautions.
What Is HeatRisk?
HeatRisk is a color-based forecast designed to describe how unusual and dangerous heat may be for a particular location. The categories range from little or no risk to extreme risk and consider both daytime and nighttime conditions.
Major and extreme HeatRisk levels are associated with a greater likelihood of health effects across larger portions of the population. Phoenix-area health data have shown increases in emergency-room visits during days classified in the two highest categories.
HeatRisk does not replace a medical assessment or local warning. It helps households understand whether the expected conditions pose a routine summer challenge or a more widespread danger.
Who Is Most Vulnerable?
Infants and young children depend on adults to control their environment and fluid intake. Older adults may have a reduced ability to sense temperature changes, while some medications and chronic conditions can interfere with cooling.
Pregnant people, outdoor workers, athletes and people without reliable air conditioning may also face greater exposure. A person does not need to belong to a high-risk category to develop heat illness during strenuous activity.
Neighbors should check on people who live alone or have limited mobility. A phone call is useful, but an in-person check may be necessary when the home is becoming dangerously hot.
What Are the Symptoms of Heat Exhaustion?
Heat exhaustion occurs after the body loses too much water and salt, often through heavy sweating. Symptoms can include headache, nausea, dizziness, weakness, irritability, thirst, heavy sweating, elevated body temperature and reduced urine output.
Move the person to a cooler location, loosen unnecessary clothing and begin cooling with wet cloths or another appropriate method. Small sips of cool water may be appropriate when the person is awake, able to swallow and not vomiting.
Medical help is needed when symptoms worsen, do not improve or involve a person with serious health conditions. Heat exhaustion can progress into heat stroke.
What Are the Signs of Heat Stroke?
Heat stroke is a medical emergency. Warning signs include confusion, loss of coordination, unconsciousness, seizures, very high body temperature and skin that may be hot and dry or still sweating.
Call 911 immediately and begin cooling the person while emergency help is coming. Move the person to shade or air conditioning, remove excess clothing and use cool water, wet cloths or ice packs around the chest, neck, armpits and groin when available.
Do not force an unconscious or confused person to drink. Delayed treatment can lead to permanent disability or death.
Never Leave Children or Pets in a Vehicle
A parked vehicle can become deadly even when the outside temperature does not seem extreme. Opening a window does not provide enough ventilation to make an unattended car safe.
The National Weather Service advises people to check the back seat every time they leave a vehicle. Children and pets should never remain inside a closed car, even for a brief errand.
Place a necessary object such as a phone, shoe or work badge near the child’s seat as a reminder. Families should also keep parked cars locked so children cannot enter them while playing.
How Much Water Should You Drink?
People should drink regularly rather than waiting until severe thirst develops. The amount required varies with age, health, temperature and activity, so individuals with fluid restrictions should follow medical advice rather than a general internet formula.
Alcohol can impair judgment and contribute to dehydration. Very sugary drinks and excessive caffeine may also be less useful than water during prolonged outdoor exposure.
Outdoor workers and athletes may need electrolytes during long periods of heavy sweating. Ordinary meals generally provide salt for less intense activities.
Use Air Conditioning When Possible
Air conditioning is the most effective protection during dangerous indoor heat. Fans can improve comfort in some conditions, but the National Weather Service warns that a fan may make a person hotter when temperatures are extremely high.
Residents without working air conditioning should identify libraries, malls, community centers or official cooling locations. Transportation should be planned before the home reaches an unsafe temperature.
Closing blinds and limiting oven use can reduce indoor heating. Those steps cannot replace cooling when the building remains dangerously hot for several hours.
Reschedule Outdoor Activities
Exercise, yard work and youth sports should be moved to the coolest practical part of the day. Frequent shaded breaks and lighter clothing reduce risk but do not eliminate it.
Coaches and supervisors should avoid using punishment or peer pressure to keep someone active after symptoms begin. A person who becomes dizzy, confused or unusually weak should stop immediately.
The NWS advises reducing strenuous activity and staying in air-conditioned locations during extreme heat. Local school and sports organizations may cancel or shorten activities when HeatRisk reaches major or extreme levels.
Protect Pets
Pets need shade, ventilation and clean water. Pavement can become hot enough to injure paws even when air temperatures appear manageable.
Walk dogs early in the morning or later in the evening and keep outings brief. Heavy panting, weakness, vomiting, confusion or collapse can indicate an emergency requiring veterinary attention.
Never leave an animal inside a parked vehicle or on a balcony without shade. Flat-faced breeds, older animals and pets with heart or respiratory conditions may overheat more quickly.
Prepare for Power Outages
High electricity demand can strain local systems during heat waves. Charge phones and medical devices, identify an alternative cooled location and keep emergency contact information available.
Anyone dependent on electrically powered medical equipment should contact the utility and health-care provider before an outage. A backup battery or generator must be used according to manufacturer safety instructions.
The Bottom Line
Extreme heat can affect healthy people as well as those in traditionally vulnerable groups. The most effective protections are air conditioning, hydration, reduced outdoor activity and early recognition of symptoms.
Heat stroke requires an immediate 911 call. Families should also check local alerts, protect children and pets from vehicles and identify a cooling location before the home becomes unsafe.
