Chronic pain is missing from America’s heat warnings

When a heat wave arrives, the public health advice follows a familiar script: drink water, watch for heat stroke, check on people with heart or lung conditions. That list saves lives. But it leaves out something that shapes daily life for millions of older Americans – chronic pain.

In a new study, public health professor Kai Zhang and I followed over 35,000 adults over age 50 across two decades, matching each person and their reports of chronic pain to the temperature history of their neighborhood.

We wanted to know whether living with extreme heat or cold – not one bad week, but months or years – changes whether pain interferes with people’s lives.

The results suggest that chronic pain deserves a place in how the country prepares people for extreme weather. They also show that rural residents may be the least protected.

What high-impact pain means

Researchers use the term high-impact chronic pain for pain lasting at least three months that limits what a person can do: work, socializing and self-care. It is not occasional aching. It is pain that affects your decisions.

For adults over 50, that matters enormously. Pain that makes it hard to stand, carry groceries or sleep through the night is a leading reason people lose the ability to live on their own.

Temperature affects the body in different ways that can lead to pain:

Cold appears to increase pain sensitivity and stiffen joints, which is why people with arthritis often brace for winter.

Heat affects the body through dehydration, broken sleep and the way it quietly shrinks the range of things a person is willing to do in a day. On hot days, for example, people may walk less, and less movement can lead to stiffer joints and weaker muscles, which makes the pain worse.

What makes heat waves dangerous is often not the afternoon temperature peak but the hot nights that don’t cool off, leaving the body with no opportunity to recover.

What we found

We tracked when each neighborhood hit temperatures that were extreme for that place. A day topping 84 degrees Fahrenheit (28.9 Celsius) in Maine, for example, would be among the hottest 5% of days there over the past decade. In Houston, meanwhile, it would have to reach 96 F (35.4 C) to be in the top 5% for heat, considered extreme.

We compared every community against its own 10-year record rather than a single national cutoff to see how months or years of exposure to extreme cold or heat temperatures in those communities affected their residents.

Two things stood out:

Among the one-fifth of our sample who lived with many extreme-cold days, reports of high-impact pain went up. However, those facing occasional cold spells didn’t report the same effect. People seemed to adapt to one hard winter, but adapting became harder over years of extreme cold.

Extreme heat was split by geography and by wealth:

• For urban residents, sustained heat showed no link to developing new pain. For rural residents, the connection was stronger. One likely reason is that people in rural areas may spend more time working outside or have older homes that are harder to cool and less access to cool places.

• Among the poorest older adults, sustained heat was also associated with a higher chance of developing high-impact pain. Among the wealthiest, it was not, likely because of better access to air conditioning, healthcare and being able to stay out of the heat.

Those who could get out of the heat were least likely to report feeling new chronic pain.

Three key lessons

Nearly every tool U.S. communities use to lower heat risk is designed for a city environment: cooling centers, tree canopy programs, urban heat island maps.

Rural areas have different challenges. Rural homes are often older and harder to keep cool. Energy costs tend to take a larger share of income. On top of that, rural hospitals have been closing across the country, leaving residents driving farther to reach healthcare.

Agriculture has the oldest workforce in the country – the average producer with decision-making roles on a farm is now about 58 years old, and nearly 40% of the farmland is owned by farmers who are 65 or older. Retirement does not move people out of the heat in rural areas, either.

The findings hold three key lessons for helping older adults:

1. Chronic pain belongs on lists of heat-related health risks, in our view. State and county heat plans flag cardiac and respiratory patients, but not the people whose independence depends on managing pain. With warning, people can plan ahead and get help, knowing chronic pain may worsen.

2. Cooling assistance programs need to be tailored to rural needs – the weatherization, energy assistance and delivery through trusted local channels that those homes need – rather than offering scaled-down versions of urban programs.

3. In the clinic, a patient’s housing and local climate details belong in their documented pain history, next to diagnosis and medication, to help better direct treatment.

Rising global temperatures are increasing the risk that people will be exposed to extreme heat for weeks at a time. In one high-risk summer, 2024, Phoenix saw 39 days with temperatures that didn’t drop below 90 F (32.2 C), even at night.

So, if you have a parent or grandparent facing a heat wave, particularly in a rural area, consider asking not just whether they’re drinking enough water to stay healthy but also whether their back or knees have been worse than usual. The pain may be connected.