Heat index warnings can save lives on dangerously hot days – if people understand what they mean

You've probably heard someone say, “It's not the heat, it's the humidity.” There's plenty of truth on this phrase, and it's vital to grasp it as summer temperatures rise.

Humidity doesn't just make you’re feeling sticky and uncomfortable – it also creates particularly dangerous conditions on hot days. Too much heat and humidity together could make you sick. And in severe cases, it could possibly cause your body to fail.

Meteorologists talk concerning the risk of warmth and humidity with the warmth indexbut it could possibly be confusing.

I'm a risk communication researcher. Here you'll learn every part you have to know concerning the heat index and the way meteorologists can higher communicate concerning the risks of maximum heat.

A construction worker in reflective clothing holds a jacket over his head to protect himself from the sun.
The risk of warmth illness may be high for outdoor employees.
Robert Gauthier/Los Angeles Times via Getty Images

What is the warmth index and the way is it measured?

The heat index is the mix of the particular air temperature and relative humidity:

  • Air temperature tells you the way hot or cold the air is. It will depend on aspects reminiscent of time of day, season, and native weather conditions. It is displayed in your thermometer in degrees Celsius or Fahrenheit.

  • Relative humidity indicates how much water vapor is present within the air and the way much water vapor the air can hold at that temperature. It is expressed as a percentage.

The heat index tells you the way it feels outside if you consider humidity. For example, if it's 98 degrees Fahrenheit (36.7 degrees Celsius) with 55% relative humidity, it would feel more like a sweltering 117 degrees Fahrenheit (47.2 degrees Celsius).

A diagram with a grid showing heat and humidity risks.
NOAA's heat index chart shows how heat and humidity mix to create dangerous temperatures.

But there's a catch: The heat index is measured within the shade so the position of the sun doesn't affect the calculation. That means should you're in direct sun, it'll feel even hotter.

Feels like temperature, warnings and wet bulb

“Apparent temperature” is one other term you may hear this summer.

The wind chill factor is the temperature you’re feeling. It takes under consideration not only temperature and humidity, but in addition wind speed. That means it could possibly tell us each the warmth index and the wind chill factor – or the mix of temperature and wind speed. It feels hotter in humid weather, and colder in windy weather.

We found that perceived temperature is even less well understood than the warmth index, possibly since the word “apparent” has different interpretations.

There are a number of other ways meteorologists discuss heat.

Wet bulb temperature takes under consideration temperature, humidity, wind and sunlight. It is particularly useful for individuals who spend plenty of time outdoors, reminiscent of employees and athletes, because it reflects conditions in direct sunlight.

Heat risk is a brand new tool developed by the National Weather Service that uses colours and numbers to point heat risks for various groups, but more research is required to know if the sort of information helps people make decisions.

In many places, the National Weather Service also issues warnings reminiscent of Monitoring, warnings and alerts for excessive heat.

The risk is that it’s going to be lost in translation

Knowledge of warmth and humidity is significant, but my colleagues and I actually have found that the term heat index will not be well understood.

We recently conducted 16 focus groups across the United States, including areas with dry heat like Phoenix and more humid areas like Houston. Many of the participants didn’t know what the warmth index was. Some confused it with the actual air temperature. Most also didn’t understand what the warnings meant, how serious they were, or when to take shelter.

In our discussions with these groups, we found that meteorologists could communicate the danger more clearly if, as an alternative of using terms like “heat index,” they focused on explaining what it seems like outside and why these conditions are dangerous.

Observations, warnings and advisories may very well be improved by telling people what temperatures to expect and when, and what steps they will take to remain protected.

A woman holds a baby at an open window with a fan blowing into it.
Clear warnings can assist residents understand their risk and protect themselves. This is particularly vital for young children and the elderly, who’re at higher risk of warmth illness.
Jason Armond/Los Angeles Times via Getty Images

Climate change is exacerbating Heat risks as a consequence of Extreme heat is becoming more commonintense and long-lasting. This implies that clear communication is required so that individuals understand their risk and know learn how to protect themselves.

How you may protect yourself

Both hot and humid conditions require extra precautions to guard your health. When you get hot, you sweat. When the sweat evaporates, it helps the body cool down. But humidity prevents sweating from evaporating. If sweat cannot evaporate, the body has problems lowering or regulating its temperature.

Although everyone seems to be in danger for health problems in extreme heat, people over 65, pregnant women, infants and young children can have problems cooling their bodies or higher risk of dehydrationCertain health conditions or medications can even increase an individual's risk for heat-related illness, so it's vital to consult with your doctor about your risk.

Heat illnesses reminiscent of heat exhaustion and warmth stroke may be prevented should you take the fitting measures. The U.S. Centers for Disease Control and Prevention focuses on staying cool, hydrated and informed.

  • Stay cool: Use air con in your property or spend time in air-conditioned spaces reminiscent of a mall or public library. Limit or postpone exercise and other outdoor activities that happen in the course of the day when it’s hottest.

  • Stay hydrated: Drink more water than usual, even should you don't feel thirsty, to assist your body regulate its temperature through sweating. However, avoid sugary drinks, caffeine or alcoholic beverages, as these may cause dehydration.

  • Stay informed: Do you already know the Signs of warmth illness and symptoms that will occur, reminiscent of dizziness, weakness, thirst, excessive sweating, and nausea. Know what to do and when to get help, because heat illness may be fatal.

Heat exhaustion causes dizziness, thirst, heavy sweating, nausea, and weakness. If you do not feel better, move to a cooler area, loosen your clothing, drink cold water, and get medical help. If you have heat stroke, which includes confusion, dizziness, and loss of consciousness, also call 911.
The difference between heat exhaustion and warmth stroke and the CDC's recommendations on learn how to behave.

image credit : theconversation.com