Updated 3 October 2026
At a glance
- One national study of psychiatric inpatients found the greatest risk of bipolar admissions on days above 30.7 °C (PubMed).
- Another study found that bipolar emergency visits decreased during high-heat periods, so heat effects differ between studies (PubMed).
- The CDC lists people with mental health conditions among those at more risk on hot days (CDC).
- Bipolar Journey keeps the day's weather note, mood, energy, sleep and medicine lines in one dated history, so hot days can be compared with cooler ones.
Hot weather can change how a day feels. For many people with bipolar disorder, the question is whether heat changes mood, energy or sleep in a way that repeats. Studies give mixed answers, so your own dated record carries the most weight for your own case.
This guide covers what the research counted, the weather and daily notes to write down, how to record medicines as dated facts, the signs that call for contact with a clinician, and a one-page summary for the visit.
Higher temperatures and bipolar hospital admissions: what two studies counted
Two peer-reviewed studies link hotter days with more hospital admissions for bipolar disorder. The first used a national claims dataset of psychiatric inpatients from 1996 to 2007 and estimated daily temperatures for 352 townships. Relative risks of bipolar disorder admissions rose with temperatures over 24.0 °C, and the highest daily temperatures, above 30.7 °C (the 99th percentile), carried the greatest risk of hospitalization.
The second followed 730 patients admitted to one hospital psychiatric inpatient unit between September 2013 and August 2015. Admissions with a primary diagnosis of bipolar disorder were associated with maximum temperature and solar radiation, and admission days also showed higher humidity and more hours of sunshine than the comparison days.
These counts describe groups of people on admission days. Your own log shows whether your days follow the same direction. Four weather facts are worth carrying into that log: the day's highest temperature, humidity when you know it, hours in direct sun, and whether the place where you slept stayed hot overnight.
From Bipolar Journey (by Health Journey Labs), we recommend writing the day's high temperature in your daily entry on any day that feels different from the day before, so that hot days and ordinary days can be compared later.
Which of your days were hot, and how did mood and energy read on them? The Daily check-in records emotional state, physical symptoms, sleep and external factors, so the weather of the day and how you felt are recorded in the same entry. In Bipolar Journey, the Daily Journal holds the exact temperature in free text or by voice entry, and the weekly and monthly views color each day by intensity, which lets you see hot days and hard days on one screen.
Why heat studies on bipolar disorder disagree: visits fell in one study
A study where emergency visits for bipolar disorder fell during hot weather
Heat research on bipolar disorder does not point one way. A study of 11 years of data from a psychiatric emergency department compared high-heat and extreme-heat days (above the 90th and 99th percentiles) with median-temperature days. Bipolar disorders visits significantly decreased (-8.6 % to -19.7 %) during high- and extreme-heat periods in both the short and long term.
The same paper reports that adjusting for school holidays reversed the association for mood disorders as a group, and its authors conclude that psychiatric responses to heat vary by disorder type, exposure duration, and thermal metric. For a personal log, a hot day is one input among several, and mood can rise, fall or stay level.
The context around a hot day
Bipolar Journey notes holidays, travel and how long the hot spell lasted.
- Holidays, travel or a day off work.
- Whether the hot spell lasted one day or several weeks.
- Whether the night was also hot.
- Any change in plans.
- Mood that day, in the same words each time.
Plans and routines around a hot spell are a normal part of the picture, and the Daily Journal in Bipolar Journey holds them as free-text notes that you read later alongside the scores. The Custom symptoms feature lets you add labels such as "holiday week" or "long hot spell", so each hot period carries its own context. Together with the Daily check-in, those labels show whether your own mood moved up, down or stayed level when the temperature climbed.
Outdoor high, indoor heat and humidity: daily weather notes for bipolar disorder
A short, repeatable weather note makes hot days easy to find later. The note works best when it uses the same four fields every day, even on days when the weather looks ordinary.
Outdoor high, indoor heat, humidity and sun
Bipolar Journey records outdoor and indoor heat separately.
| What to write | Example entry | Why it helps |
|---|---|---|
| Outdoor high | "High of 95 °F, sunny." | Lets you group days by temperature band. |
| Indoor heat | "Bedroom warm all evening." | Separates the weather outside from the room where you spent the hours. |
| Humidity or air feel | "Heavy air, no breeze." | Matches the humidity measure used in research. |
| Time in sun | "Two hours outside at midday." | Matches the solar radiation measure. |
The CDC lists people with mental health conditions among the groups that may be more at risk on hot days, and it also lists people who lack access to cooling. The indoor note therefore records a real part of your day.
The weather note goes into Bipolar Journey in one place each day. The Daily check-in carries external factors, and the Daily Journal takes the exact numbers as typed text or as a voice entry. Because every entry lands in the same dated history, the calendar view shows which dates carry a hot-day note and how those dates compare with the rest of the month.
Mood, energy, activity and concentration on hot days with bipolar disorder
The NIMH describes bipolar disorder as a mental illness that causes clear shifts in a person’s mood, energy, activity levels, and concentration. Those four areas make a natural set of entries for a heat log. Use the same wording on hot days and on cooler days so the two groups can be compared fairly.
Mood, energy, activity and focus on hot days
Bipolar Journey compares these four on hot and ordinary days.
| Area | What to write on a hot day | Example wording |
|---|---|---|
| Mood | The word you would pick for the day, plus a score if you use one. | "Irritable by noon, flat by evening." |
| Energy | How much you had for ordinary tasks. | "Wired until late, then spent." |
| Activity level | What you did compared with a usual day. | "Rearranged the whole room; skipped lunch." |
| Concentration | How long you could stay on one task. | "Lost my place in the same email three times." |
If a day was clearly different from your usual range, mark it and add the temperature note, so hot and cool days are easy to compare later.
From Bipolar Journey, we recommend keeping the area names identical from day to day. Identical names are what allow a comparison of hot-day entries with the rest of the month.
Four areas, one entry: the Daily check-in in Bipolar Journey records emotional state and physical symptoms, and the Flare Tracker flags a day that stands out from your usual range. Reading flagged days against the weather note shows whether the standout days gather on the hottest dates. The Daily Journal adds the words you used for the day, which a score alone cannot hold.
Hot nights, sleep, caffeine, alcohol and meals in a heat spell with bipolar disorder
A hot spell often changes sleep hours and the way meals and drinks are spread through the day. These details are easy to forget and easy to compare, so record them as plain observations.
Hot nights, caffeine, alcohol and meals
Bipolar Journey notes whether the room was hot overnight.
- Sleep hours. Write the hours slept and whether the room was hot.
- Caffeine. Write how many cups and roughly when.
- Alcohol. Write whether you had any and how much.
- Meals and drinks. Write which meals you had and what you drank through the day.
- Next-day mood. Write one line the morning after a hot night.
Read together, those lines show whether hot nights are followed by different mornings. The guide on how short sleep affects the next day's mood describes how to read sleep hours against the following day, and the guide on starting a sleep and mood log covers the daily basics if your log is new.
Sleep, caffeine, alcohol and meals each have their own place in Bipolar Journey. The Daily check-in records sleep and nutrition, and the Food Tracker keeps meal or drink lines with caffeine and alcohol. When you read the Food Tracker against sleep hours and the next day's mood, the hot-night mornings are easy to pick out from the rest.
Medicines and heat with bipolar disorder: dated facts to bring to a clinician
The CDC states that many medications, including over the counter medications, can impair heat tolerance and the body's ability to regulate its temperature. A page of dated facts helps a clinician see exactly what you took and how the hot days went.
Record these medicine facts as they are, with no change to your routine:
Medicines and storage in hot weather
Bipolar Journey lists every medicine and supplement you take.
- The names of all medicines and supplements you take, including those bought without a prescription.
- The times of day you take each one.
- Any new symptom on a hot day, such as dizziness, unusual thirst or a change in sweating.
- Where you store medicines during a hot spell.
A useful visit question takes this form: "Is it worth reviewing my medicine list together before the next hot spell?" The clinician decides what, if anything, changes.
From Bipolar Journey, we recommend bringing the list of names and times to that visit, with the hot-day entries attached to it.
The My Meds tracker in Bipolar Journey records the names of the medicines you already take as prescribed, along with their timing. Read against sleep hours and next-day mood, it lets a clinician review the medicine list alongside the hot-day entries. The Daily check-in adds any physical symptom you noticed on the same date.
Bipolar disorder in a heat spell: get help for danger or thoughts of suicide
Urgent help with bipolar disorder in a heat spell: who to contact
The CDC lists hospitalizations and emergency department visits for mental health conditions among the outcomes associated with hot days. No fetched authority page lists warning signs for bipolar disorder in the heat, so the guidance here is short.
Contact a clinician when your mood, energy or thinking change quickly over a hot spell, or when the change worries you or the people around you. Describe the dates and what you noticed, and bring the log if you have it.
If there is danger, call your local emergency number (911 is one example). If you have thoughts of suicide or of hurting yourself, call your local emergency number (911 is one example) or a crisis line where you live (988 is one example in the US). The NIMH page on bipolar disorder lists call or text the 988 Suicide & Crisis Lifeline as one such option in the United States.
Help comes first and logging comes after.
Once you are safe, the Flare Tracker in Bipolar Journey marks the day that stood out so that the dates are easy to find afterward. The Daily check-in and the Daily Journal then supply the mood, sleep and weather lines around that date for the clinician to read.
Heat notes for a bipolar disorder visit: dates, temperatures and a one-page summary
A visit about heat and mood goes best with a short, dated record. Bring a small set of items, each tied to a date:
Hot-day entries to bring to the clinician
Bipolar Journey brings the hottest dates and the entries for those days.
- The hottest dates of the season and the mood, energy, sleep and activity entries for those dates.
- The dates you flagged as clearly different from your usual range.
- Hot nights and the hours of sleep that followed.
- The medicine names and times from the same weeks.
- Two or three questions, such as "Is it worth reviewing my medicine list together before the next hot spell?"
Group the entries by hot spell instead of by single day, because a clinician looks for a stretch of days that moved together. The guide on entries that go beyond one mood score lists further items worth writing between hard weeks. A log that shows no link between heat and mood is a useful answer as well.
For the visit itself, the Doctor Report in Bipolar Journey exports a one-page summary of the logged history, including dates, sleep and mood context and how you functioned. The My Care Team tracker holds the clinicians you see and short visit notes, so your questions about heat and the answers you receive stay together with the entries they refer to.
How Bipolar Journey can help
A paper notebook or a notes app can hold a temperature and a mood word for a few days. Once you want hot days, sleep hours, medicines and visit questions in one place, a dedicated tracker keeps them together. A comparison of options is in Best Bipolar Apps 2026.
Bipolar Journey is a personal bipolar disorder tracker from Health Journey Labs on the App Store and Google Play. It lets you record the weather of the day, mood, energy, sleep and medicine lines in one entry and flag the days that stand out. Over a hot season those dated entries show whether heat and your own days move together, and they give a clinician specific dates to read. Below is what you can use and how each part helps.
- Daily check-in — A guided daily form for physical symptoms, emotional state, nutrition, sleep, exercise, meds and external factors such as the weather of the day.
- Daily Journal — Free-text and voice notes for the exact temperature, the room you slept in and how the day felt in your own words.
- Flare Tracker — Flags a day that clearly stands out so hot-spell dates are easy to find and compare across weeks.
- My Meds — Records the names and timing of the medicines you already take as prescribed, to read against sleep hours and next-day mood.
- My Assessments — Structured check-ins that go beyond the daily scores, plus the life and social context from onboarding.
- Learn — Short education topics and prompts on sleep, mood, routines and visit preparation, read alongside your own logged weeks.
- AI companions — Clara for general chat and specialist companions on knowledge, fitness, nutrition and relationships, all of which see your logged history.
- Weekly Goals — One small aim for the week and a record of whether it held, set against your real check-ins.
- Doctor Report — A one-page summary exported from your logged history, with dates, sleep and mood context and how you functioned.
- My Care Team — Lists your clinicians and holds short visit notes, for preparation, notes during the visit and review afterward.
- My Labs — Result dates for blood counts, levels and other tests, read against sleep, mood and function.
- Period Tracker — Start and stop dates, flow and how heavy or light bleeding felt, read with sleep, mood and energy.
- Food Tracker — Meal or drink lines with caffeine and alcohol, read against sleep and mood.
- Weight Tracker — Scale readings or body notes, when they matter for your angle.
Everything you log builds one history, and insights get stronger as it grows. Custom symptoms let you add your own labels.
We make Bipolar Journey at Health Journey Labs. This guide is educational and does not replace medical advice. Diagnosis, medication decisions, and urgent care decisions belong with your treating clinicians.
Sources
- CDC — Clinical Overview of Heat
- NIMH — Bipolar Disorder
- PubMed — A positive relationship between ambient temperature and bipolar disorder identified using a national cohort of psychiatric inpatients
- PubMed Central — Maximum Temperature and Solar Radiation as Predictors of Bipolar Patient Admission in an Emergency Psychiatric Ward
- PubMed — Effect of ambient temperature and thermal comfort indices on emergency visits for psychotic and mood disorders
FAQ
The answers below draw on the sources cited in this guide, and the app they mention is Bipolar Journey (by Health Journey Labs).
Can hot weather trigger bipolar episodes?
Some studies link hotter days with more hospital admissions for bipolar disorder, and one study of emergency visits found fewer visits on very hot days. Results differ by study design, so heat is best treated as one possible input among several.
Bipolar Journey lets you place a weather note in the Daily check-in as an external factor. After a few hot spells, the calendar view shows whether your own difficult days gather on hot dates or spread across the month.
Does heat push mood up, down or both?
Research reports both directions, and the answer can differ between people and between hot spells. The best evidence about your own mood is a record of how you felt on hot days compared with cooler days across a season.
With Bipolar Journey, the Daily check-in keeps emotional state in one place and the Daily Journal keeps your own words. Reading the two against the weather note shows whether hot days lean up, down or neither for you.
Which temperature should I write down each day?
Write the day's highest outdoor temperature, and add the indoor feel if your home or workplace was hot. One number and a few words are enough, as long as you use the same pattern each day.
The Daily Journal in Bipolar Journey takes the number as typed text or voice entry, so the weather detail goes in alongside the day's other notes. Later you can group dates by temperature band without searching through memory.
Should I record indoor heat as well as the outdoor temperature?
Yes, when you spent hours indoors. The CDC lists people who lack access to cooling among those at greater risk on hot days, so the indoor note records a real part of the day that the outdoor number misses.
Bipolar Journey keeps the indoor note in the same dated history as the outdoor high. The Custom symptoms feature lets you add a label such as "hot bedroom", and the monthly view then shows how often that label appears.
How can I tell a heat effect from an ordinary mood swing?
A single day cannot answer this. Several hot days and several cooler days, each logged with the same mood, energy and sleep entries, give a fair comparison, and a repeated difference across hot spells is the signal to bring to a clinician.
The Flare Tracker in Bipolar Journey flags days that stand out from your usual range. When flagged days cluster around the hottest dates over several weeks, that cluster is concrete evidence to show at a visit.
Do hot nights change sleep and mood the next day?
They can for some people, and the way to find out is to record the hours slept, whether the room was hot, and the next morning's mood. A clinician can help you read the result.
The Daily check-in in Bipolar Journey records sleep and emotional state in one entry. After a hot spell, you can read the hot-night mornings against the cooler ones and bring that comparison to a clinician.
Do my medicines change how I handle heat?
The CDC notes that heat tolerance and temperature regulation can be affected by many medications, including those bought without a prescription. A clinician or pharmacist can say whether that applies to what you take.
The My Meds tracker in Bipolar Journey keeps medicine names and timing as dated facts. Your visit question can then take this form: "Is it worth reviewing my medicine list together before the next hot spell?"
What should I do if I feel much worse on a hot day?
Contact a clinician when your mood, energy or thinking change quickly or worry you. For danger, or for thoughts of suicide or of hurting yourself, call your local emergency number (911 is one example) or a crisis line where you live (988 is one example).
Once the immediate situation has passed, the Flare Tracker in Bipolar Journey marks the date of the day that stood out, and the other entries around it are ready to share with the clinician who sees you.
Is heat worth raising with my clinician?
Yes, if you see a pattern across more than one hot spell or if hot days worry you. Bring dates, temperatures, sleep hours and mood entries, and keep the questions in the form "Is it worth reviewing this together?"
The Doctor Report in Bipolar Journey exports a one-page summary of the logged history, including dates, sleep and mood context and how you functioned. The clinician reads the hot-spell entries in a few moments and can ask about the details.
How many hot spells do I need to log before a pattern shows?
No source gives a fixed number for this question. Two or three hot spells with matching entries give a first impression, and each additional spell makes the comparison more reliable for you.
Insights in Bipolar Journey strengthen as the shared history grows. The weekly and monthly views color days by intensity, so repeated hot spells with similar colors become visible without any extra effort.
What if my mood feels better in the heat?
A better mood on hot days is also worth recording. The emergency-department study above found fewer bipolar visits during high-heat periods, and elevated mood can still come with changes in sleep or activity that a clinician would want to know about.
Use the Daily check-in in Bipolar Journey to record the lift together with sleep hours and activity. If you flag the day with the Flare Tracker, the entry stays easy to find for a visit.
Do humidity and sunshine matter as well as temperature?
The hospital study of 730 patients found that bipolar admission days had higher humidity, more solar radiation and more hours of sunshine than comparison days, alongside higher temperature. Writing one line about each gives you the same details to review.
Bipolar Journey lets the Daily Journal hold a line such as "humid, two hours in direct sun" alongside the Daily check-in scores. Over a season, you can see which weather details travel with your harder days.
How do I log a hot day when I am too low or too wound up to write much?
Keep the minimum: the temperature, one word for mood and one word for energy. A short entry on a difficult day is more useful than a long entry that never gets written.
The Daily Journal in Bipolar Journey accepts voice entry, so a spoken note can replace typing. The Custom symptoms feature adds a label such as "hot day", which keeps the date findable.
Can an AI chat help me read my heat and mood notes?
General chat tools only see what you paste in, which can leave out weeks of context. Anything an AI says about your mood or medicines belongs in a conversation with a clinician before you act on it.
The AI companions in Bipolar Journey, including Clara, see your logged history, so their answers can refer to your actual hot-day entries. Use them to prepare visit wording and a short list of questions for a clinician.
What privacy steps make sense for a health log?
Mood entries, sleep hours and notes from a hard week can be read out of context by someone who was not there. Keep the log behind a passcode, avoid shared devices, and agree with your clinician or a trusted person on what you share and when.
Entries in Bipolar Journey are your own health notes, and the app's privacy policy describes how data is stored and handled, so read it before adding sensitive details. This guide gives general information, and medical advice comes from your clinician.