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The thermostat wars
Nobody warns you that the argument that never ends in a house with three generations won't be about money or medicine. It will be about the thermostat. You're sweating in a house set to 78. Your mother is in a cardigan asking who left it so cold. Both of you are telling the truth.
Their 78° is not your 78°
The National Institute on Aging (NIA) says it plainly in its cold-weather advice: aging, health problems and medicines can all affect how well a person stays warm, and how well they notice that they are getting dangerously cold.[2] Two bodies in the same room feel two different temperatures. And the older body is worse at telling when it is too cold.
This page used to go further. It described changes in the brain, in sweating and shivering, in blood flow to the skin, and types of drugs that change how warm a person feels. That may all be true. But we could not re-open the research it cited to check what it really said. So we took the detail out. We will not keep sources we cannot stand behind. The bottom line does not change: your parent is not being difficult.
The study people quote, and how small it is
One finding gets quoted every time this comes up. Know how small it is before you use it in an argument. Researchers followed 47 older adults in Boston for 12 months. They measured the temperature in their homes and asked about trouble paying attention. People reported the least trouble between about 68 and 75°F. The odds of trouble about doubled for every 7°F outside that range.[1]
What that is: 47 people describing their own attention while researchers watched the temperature. What it is not: a safe range for everyone's brain, a medical test, or proof that changing the thermostat changes anyone's thinking. If your father seems foggier on cold days, this study is a reason to notice the pattern and mention it to his doctor. It is not proof that you have found the cause.
Used with care, it still helps. It gives the family a range to bargain around, not just two opinions. And inside a range, there is a number you can both live with.
The safety minimum, which is a separate question
NIA says to keep the heat at 68°F or higher during cold weather.[2] That is not about comfort or attention. It is because an older body can get into trouble without much warning. That is also why, during a heat wave or a cold snap, checking on someone beats asking them how they feel.
If you think someone has hypothermia (a dangerously low body temperature), it is an emergency. Call 911.[2]
Calling the truce
- Warm the person, not the house. Set the shared rooms as warm as the rest of the family can stand. Then close the gap on their side: warm socks and slippers, a lap blanket, a cardigan kept on their chair.
- If you add a heater, follow the heater rules. The Consumer Product Safety Commission (CPSC) says to keep a portable electric heater at least three feet from anything that can burn, plug it straight into a wall outlet and not into an extension cord or power strip, and turn it off when no one is watching it or while sleeping.[3] Use it in their room only, away from bedding.
- Heat rooms separately where you can. A closed door and a cheap room thermometer beat one thermostat ruling everybody. If the house can heat each area by itself, or their room has its own unit, this argument mostly ends.
- Aim the shared rooms at 68–75°F to start, based on the study above. Then adjust by what people really say.
- Make a list so you don't have the same talk again. Which rooms people use, the temperature in each, where the drafts are, what each person wears, and what feels comfortable to them. Agree on when you will check it again in unusual weather. What the older person wants belongs on that list too.
- Take a sudden change to the doctor, not the thermostat. If someone is cold all the time and that is new, tell their doctor. NIA says health problems and medicines affect how well a person stays warm.[2] The questions to ask shows how to bring it up.
One caution about using any of this: a range from a study is not a reason to wave off someone's discomfort or explain away a new symptom.
Quick answers
Why is my elderly parent always cold?
Aging, health problems and medicines can all affect how well a person stays warm, and how well they notice when they are dangerously cold. That is how the National Institute on Aging (NIA) puts it, and it is why "just put a sweater on" misses the point. This page used to explain the body science in detail, with named parts of the brain and types of drugs. We took that out because we could not re-open the research it came from. If someone starts feeling cold in a new way, or it does not go away, bring it up with their doctor. Don't try to solve it at the thermostat. [2]
What indoor temperature is best for seniors?
People quote one study, and it is smaller than the headlines suggest. Researchers followed 47 older adults in Boston for 12 months. They measured the temperature at home and asked about trouble paying attention. People reported the least trouble between about 68 and 75°F. The odds of trouble about doubled for every 7°F outside that range. But this was 47 people describing their own attention. It is a useful number to bargain around, not a doctor's order. Separately, NIA says to keep the heat at 68°F or higher in cold weather. [1, 2]
How do families settle thermostat disagreements in a shared house?
Set the shared rooms at a number everyone can live with. Then close the gap on the older person's side with layers, a lap blanket, and extra warmth in their own room, not the whole house. If you use a portable electric heater, the Consumer Product Safety Commission (CPSC) says to keep it at least three feet from anything that can burn, plug it straight into a wall outlet, and turn it off when no one is in the room or when you sleep. If your heating lets you set each room by itself, that ends the argument. [3]
Sources and what they support
Sources checked 2026-09-17 and 2026-09-19 using AI-assisted editorial research. This is a source check, not a clinical review.
- Baniassadi et al., home temperature and attention in older adults (PMID 39656181). Supports the 47 participants in Boston, the 12-month observation, the lowest odds of reported attention difficulty between roughly 68 and 75°F, and the doubling of odds about every 7°F outside that range. An observational study of self-reported attention in a small sample: it cannot establish cause, does not set a safe or unsafe temperature, and 47 people in one city is not a national finding. Checked from the published abstract on 2026-09-17; the abstract page is CAPTCHA-gated and was not re-opened on 2026-09-19.
- National Institute on Aging, cold weather safety for older adults. Supports the advice to keep home heating at at least 68°F in cold weather, that aging, health conditions and medicines can affect both the ability to stay warm and the ability to notice dangerous cold, the instruction to treat suspected hypothermia as an emergency, and the direction to raise new or persistent changes in temperature tolerance with a clinician. General public safety guidance for cold weather: it does not quantify comfort at any temperature, does not address heat, and is not a substitute for the person's own doctor on why they feel cold.
- US Consumer Product Safety Commission, space heater, furnace and fireplace warning (2023). Supports the three specific precautions used here: keeping a portable electric heater at least three feet from combustible materials, plugging it directly into a wall outlet rather than an extension cord or power strip, and turning it off when unattended or while sleeping. A consumer safety advisory from 2023 about portable heating equipment generally. It does not evaluate any particular heater, does not cover fuel-burning appliances' carbon-monoxide precautions in detail, and following it does not make a heater safe in a room with someone who may not remember it is on.
This page's prose is the version that was live before the 2026-09-17 citation pass, with the citations attached to it and the claims trimmed to what the sources support. Removed for want of a retrievable source: the detailed physiology of aging thermoregulation and the named medication classes, which rested on two CAPTCHA-gated reviews; the attribution of the attention finding to an institute blog post rather than the study; and the framing of the study range as a "cognitive-health setting".