Dementia and Extreme Heat: What Every Care Partner Needs to Know

By Rachel Whyte, RN, CEN, CDP

When a heat wave moves in, most of us feel it and respond. We reach for water, move indoors, change what we're wearing, and look for shade. These responses feel automatic, but they're not. They depend on a brain that can accurately sense temperature, process discomfort, generate thirst, and then act on all of it in a coordinated way.

For people living with dementia, that chain breaks down at almost every link. And during extreme heat, that breakdown can become a medical emergency quickly and quietly.

This post is for care partners, family members, and anyone supporting a person living with dementia through the increasingly common reality of dangerous summer heat. Understanding what makes dementia and heat such a serious combination, and knowing what to do about it, can be the difference between a difficult day and a trip to the emergency room.

Why Heat Is Different When You Have Dementia

The human body regulates temperature through a finely tuned system controlled by the hypothalamus, a region of the brain that continuously monitors core body temperature and triggers the right responses: sweating, increased blood flow to the skin, seeking a cooler environment. Dementia, particularly Alzheimer's disease, damages the neural pathways involved in this process. The thermostat, in effect, becomes unreliable.

This has several consequences that compound each other during extreme heat.

The thirst signal weakens. 

Older adults already experience a blunted sensation of thirst compared to younger people, and dementia reduces it further. A person with dementia can be significantly dehydrated without feeling thirsty, without reporting it, and without connecting their discomfort to the need for water. By the time someone appears visibly unwell, dehydration may already be serious.

The ability to self-regulate behavior is affected. 

Someone living with dementia may not notice that the house is too hot. They may not think to remove a sweater or move from a sunny room to a shaded one. They may resist taking a cool drink because it disrupts their routine, or they may simply not recognize that what they are experiencing is heat-related. The cognitive architecture that generates and executes appropriate responses is the same architecture dementia erodes.

Medications add another layer of risk 

because many medications may affect the body's ability to respond to heat. Anticholinergic drugs reduce the ability to sweat. Diuretics increase fluid loss. Some antipsychotics impair the body's heat dissipation mechanisms. Medications that are managed safely in normal temperatures can become a significant risk factor during a heat wave (Centers for Disease Control and Prevention, 2025). A review with the prescribing physician before summer, or when a heat wave is forecast, may be worthwhile.

Communication difficulties mean symptoms go unnoticed. 

Heat exhaustion does not always announce itself clearly. A person with dementia who is becoming dangerously overheated may appear more confused than usual, more agitated, more withdrawn, or simply quieter. They may not have the language to say they feel unwell, or they may not connect the feeling to a cause. Care partners are often the only line of detection, which means knowing what to watch for matters enormously.

What Heat Illness Looks Like

Heat illness exists on a spectrum.

Heat exhaustion is the earlier stage, and heat stroke is the medical emergency.

Signs of heat exhaustion include heavy sweating, cool and pale or clammy skin, a fast but weak pulse, nausea, dizziness, and fatigue. The person may seem more confused or disoriented than usual. This stage is serious and requires immediate cooling and hydration, but it is recoverable.

Heat stroke is a life-threatening emergency. The body has lost its ability to cool itself. Signs include a body temperature above 103°F (39.4°C), hot and red skin that may be dry or damp, a rapid and strong pulse, and possible loss of consciousness. In people living with dementia, a sudden and severe increase in confusion or agitation during hot weather should always prompt an urgent check of temperature and immediate medical attention if heat stroke is suspected. Call 911 immediately.

Between these two states, the signs in a person with dementia can be subtle. A person who is more confused than usual, more withdrawn, less interested in eating or drinking, or noticeably fatigued during a heat wave should be assessed immediately for heat-related illness. Do not wait for the more obvious signs.

Practical Ways to Protect Someone with Dementia During Extreme Heat

Keep the home cool, and check it often.

Air conditioning is the most effective protective measure during a heat wave. If air conditioning is not available, fans combined with wet cloths can help, though they are less effective when temperatures are very high. Check the temperature of the home regularly, particularly in rooms that get direct sun, and close blinds and curtains during the hottest parts of the day to prevent heat buildup.

Remember that a person living with dementia may not move out of a hot room unprompted, even if they are uncomfortable. Check on them frequently rather than assuming they will seek relief on their own.

Offer fluids consistently and creatively.

Rather than waiting for a person to ask for water, build hydration into the structure of the day. Offer a drink with every meal, medication, and activity. If water is refused, try other options: diluted juice, herbal tea, broth, or water-rich foods like watermelon, cucumber, or yogurt.

Many people living with dementia accept a cold drink more readily when it is offered naturally in the course of conversation rather than presented as a health task. You probably need to hydrate as well, so grab a beverage yourself and say, "Cheers!"

Simplify clothing.

Lightweight, loose-fitting, light-colored clothing helps the body manage heat. Some people living with dementia may resist changing clothes or insist on wearing familiar items regardless of the weather. Gentle redirection works better than confrontation. If a particular sweater is being insisted on, try offering it as an option for later in the day and redirecting to something cooler in the moment.

Limit outdoor activity during peak heat hours.

If going outside is part of the daily routine, plan it for early morning or evening when temperatures are lower. Even brief sun exposure during a heat wave can be risky for someone with dementia, particularly if they are taking medications that affect thermoregulation. Shade, hats, and sunscreen matter during any outdoor time.

Review medications with the care team.

It's good to know, in general, whether a medication may increase heat sensitivity or make the person you are caring for more susceptible to dehydration. When in doubt, ask a pharmacist. Diuretics, anticholinergics, and certain antipsychotics are the most common concerns, but any medication that affects fluid balance or the nervous system is worth reviewing.

Do not adjust or stop medications without medical guidance, but be aware of potential side effects during periods of extreme heat.

Know the cooling centers in your area.

Many communities open public cooling centers during heat emergencies, including libraries, community centers, and shopping malls. If the home cannot be kept cool, these are a legitimate and sometimes necessary option. Plan in advance for how you would get there, and make sure it is an environment the person with dementia can manage without becoming overwhelmed.

Check in more frequently.

Heat waves are not the time to extend the gap between visits or calls. If you are not the primary care partner but are involved in someone's care, increase your check-ins. A daily call or visit during extreme heat can catch early signs of heat illness before they escalate.

A Note on Sundowning and Heat

Care partners who are already managing sundowning—the increase in confusion and agitation that often occurs in the late afternoon and evening—should be aware that heat can intensify it significantly.

Dehydration, physical discomfort, and cognitive load from a hot, uncomfortable environment all converge during the late afternoon hours. Prioritizing cooling, hydration, and calm during that window can reduce the severity of sundowning episodes during a heat wave, even if the strategies that normally help feel less reliable on the hottest days.

The Bottom Line

Extreme heat is a genuine health risk for people living with dementia, and it is one that requires active management by care partners because the person themselves may have no reliable way to recognize or respond to it. The protective strategies are not complicated, but they do require consistency and attention during a time when the heat itself makes everything feel harder.

Stay cool. Stay hydrated. Keep a close eye on changes in behavior, appetite, or energy level. And do not hesitate to seek medical help if something seems wrong.

During a heat wave, acting early is always the right call.

How Simon Can Help

At Simon, our shared tools help care partners stay coordinated on exactly the kinds of daily checks that matter most during a heat wave: hydration reminders, medication schedules, and shared task lists that keep everyone involved in care aligned.

Our dementia course also covers the daily habits and environmental strategies that help protect health, promote independence, and support living well with dementia throughout every season.

Download the Simon App | Learn More About our Dementia Course

References

Centers for Disease Control and Prevention. (2025, September 18). Heat and medications: Guidance for clinicians. U.S. Department of Health and Human Services. https://www.cdc.gov/heat-health/hcp/clinical-guidance/heat-and-medications-guidance-for-clinicians.html