Ancestors, Heat Waves, and the Records They Left Behind

I've been thinking about heat lately with the Northeast sweltering this week. What about the kind of heat your ancestors dealt with every single summer with zero mechanical help? No central air. No window unit humming in the background. No thermostat. Just July, and whatever they could figure out.

We talk a lot about what people did to stay cool before air conditioning. But as a genealogist, what I actually want to know is what those summers left behind. We can find records, newspapers, death certificates that all point to the effects of extreme heat.

Those records are there. You just have to know where to look.

"Heat Prostration" on a Death Certificate

If you've been doing death certificate research long enough, you've probably seen it: heat prostration, sunstroke, prostration, sometimes just exhaustion. These were real causes of death listed by physicians, and they weren't rare.

Summers before air conditioning killed people; a lot of them. A heat wave in the summer of 1896 produced around 1,500 deaths from the Midwest to New England alone. These spikes show up in the records. If you have an ancestor who died in July or August in a hot year and the cause of death looks vague, heat-related illness is worth considering, especially if they were elderly, an infant, or living in a dense urban area.

Death certificate noting heat prostration as the cause of death. Curtesy of the Maryland State Archives.

The U.S. began using the International Classification of Diseases coding system around 1900, which means many death certificates after that date include a numeric code alongside the written cause of death. If you're looking at a certificate where the handwriting is unclear or the terminology is unfamiliar, that code can help you pin down exactly what was recorded. Historical ICD code references are available online and are a genuinely useful tool for this kind of interpretation.

The Architecture Tells You Something Too

Before anyone could buy their way out of summer, buildings had to do the work. High ceilings let hot air rise and escape. Porches provided shade and airflow. Stone and brick held cool temperatures better than wood. Homes were oriented to catch the prevailing breeze, and windows were placed for cross ventilation.

An example of a Sanborn Map from the Library of Congress. The dotted lines on the dwelling represent porches.

This matters to your research because vernacular architecture (the building style specific to a region and its climate) is a clue about where your ancestors actually lived and what their daily conditions were. A sleeping porch listed on a property record or visible in an old photograph isn't decorative. It tells you something about the household's resources, the era, and sometimes the health conditions in the family. Sleeping porches were even incorporated into sanatoriums because outdoor air was thought to help fight tuberculosis, and that association carried into residential construction.

Look for historical pictures or use Sanborn or other Fire Insurance maps to see if your ancestor's home had a porch, a second floor, etc., that may effect how they dealt with heat.

Historical Newspapers Are Full of Heat Wave News

Summer heat made news. Deaths, warnings, advice columns, reports from the city coroner's office - local newspapers covered all of it. In Chicago in 1916, a court clerk described his telephone ringing "constantly for nearly two hours" as doctors turned in heat death report after report. That reporting exists. A lot of it has been digitized.

If you have an ancestor who died in summer under circumstances that feel unexplained, pull the local newspaper from that week. Heat waves generated public health coverage, mortality tallies, and sometimes names. The same goes for urban living conditions — tenement coverage, fire escape ordinances, city health commissioner statements. These are the kinds of sources that put flesh on a vital record.

Newspaper archives worth checking: Chronicling America (free, Library of Congress), GenealogyBank, Newspapers.com, Newspaperarchive.com, and your state's digitized newspaper collections, many of which are free through state library systems.

The Cabbage Leaf Trick (Yes, Really)

If you've ever heard that Babe Ruth wore cabbage leaves under his cap, that's not a myth. During games, Ruth kept cabbage leaves chilled in a cooler and wore one or two of them under his cap, swapping them out every few innings as they warmed up. Baseball uniforms of that era were made from wool — worn in the July sun, in stadiums that were designed with essentially no thought given to airflow or shade. The man was resourceful.

Cooled cabbage leaves were put in hats to help people keep cool.

Ruth eventually shared the trick with his teammates, which tells you something: this wasn't so eccentric that other people wouldn't try it. Keeping the head cool was a genuine priority in a world where you couldn't escape into air conditioning between innings.

This detail matters genealogically in a small but real way: it's a window into what daily life in summer actually felt like for people working outdoors, in factories, on farms, or in any other physical capacity before the mid-20th century. The heat was a constant presence. People developed systems for managing it. When you see "heat prostration" on a death certificate, this is the world that entry came from.

What They Actually Did, and What Records It Left

People got creative. At night, city families dragged mattresses onto fire escapes or headed to a nearby park to sleep where there was a breeze. It got bad enough that housing inspectors started fining people for blocking fire escapes with their bedding — which means those fines and ordinances are in city records. Families with means left for the coast or the mountains entirely, which might explain a sudden gap in your city directory or an unexpected appearance in a resort town's local paper.

During the day, people kept windows and doors shut at midday and delayed cooking until evening. Awnings covered nearly every window on city buildings by the late 19th century — a detail worth noting when you're looking at old photographs of a neighborhood where your family lived.

Newspaper (Every Evening) in Wilmington, DE 3 August 1928

None of this is in the vital records. But it's in the newspapers, the city ordinances, the property records, and the photographs. That's the whole point of researching daily life alongside the documents: the records tell you what happened. The context tells you what it was actually like to live it.

Understanding Their Lives, Even When the Records Are Silent

Not every ancestor who sweated through a brutal August ended up in a heat-related record. Most of them didn't. They survived, went back to work, and left behind the usual paper trail — census entries, land records, church minutes, letters if you're lucky.

But understanding what their summers actually looked like still changes how you read those documents.

An ancestor who lived in a dense city tenement in the 1890s wasn't just a name on a census page. She was someone who may have slept on a fire escape in July, who kept her windows shut at midday to hold in whatever cool air she had from the night before, who delayed cooking until evening because lighting a stove in August was its own kind of misery. Her neighbor's baby may have died in a heat wave that summer — the kind that killed 1,500 people across the Midwest and New England in 1896 — and that death would show up in the records even if hers didn't.

The social fabric of life before air conditioning was shaped by heat in ways we don't think about anymore. Porches weren't just architectural features — they were where people actually lived in summer, where neighbors talked, where community happened in the evening when the day finally cooled down. Parks filled up at night with families who had nowhere else to go. The rhythm of daily life shifted around the season in ways that are completely foreign to anyone who grew up with central air.

When you understand that context, you read your ancestor's world differently. A note in a church record about a prayer meeting being held on the lawn instead of inside. A newspaper mention of a family spending two weeks at a lake cottage. A gap in a city directory because someone left for the country in July. These aren't random details. They're people managing their lives in a world where summer was something you had to actively survive.

The records that survive are only part of the story. The life around them is the rest of it — and that life had a temperature.

The Practical Takeaway

If you have an ancestor who:

• Died in July or August with a vague or unfamiliar cause of death

• Lived in a dense urban area or worked outdoors

• Was elderly, very young, or already ill

  
  

…heat-related illness is worth researching. Pull the death certificate and look for ICD codes alongside the written cause. Check the local newspaper for that week. Look at city health department records if they exist for your area. And if the cause of death reads "prostration" or "exhaustion" and you've been treating it as a dead end — it isn't. It's a starting point.

Your ancestors survived a lot of summers. The ones they didn't are in the records. You just have to know what you're looking for.