Extreme heat is a
wicked problem
No single cause. No single owner. No finish line.
Shade is something we hold up together.
Understand how heat harms people, choose protection for your place, and work out who could act and who could pay.
A free, sourced journey through how extreme heat harms health, income and homes across South and Southeast Asia, how one harm leads to the next, and what helps. Built with, and for, the people working on it.
Every consequence is sourced, and where the evidence is thin, the map says so.
Five short acts, about fifteen minutes. Free, no sign up, and what you choose stays in your browser.
I work as:
Each opens a short path, with how long each stop takes. Your choice stays in this browser.
Act 1Feel it
What does a hot day do to people?
Before any diagram: a single hot day, lived by people at home, at work and in the services everyone depends on. Each moment is drawn from the evidence.
- An older woman living alone
She has a fan but rations it to keep the electricity bill down. On a hot night she falls ill, the cost of care adds to what she owes, and next summer she can afford to run the fan even less.
- A nurse at a primary health centre
On the hottest days the waiting room fills with people who are dizzy, vomiting or confused. With so many waiting, some are seen late, and by then their illness has become more serious.
- A water-pump operator on the city’s edge
During a heatwave the power fails, so the pumps stop and taps run dry. Meanwhile the power station upstream is short of water to cool itself, and the cuts come more often.
- A neighbourhood gardener
She waters the street trees she planted years ago, but a hot, dry summer still kills some of them. Without their shade the pavement heats up, and the trees that remain struggle even more.
- A girl in her early teens
When heat closes her school for weeks and money is tight at home, she starts helping her mother instead. She falls behind, and each year it becomes harder for her family to send her back.
- A day-wage construction worker
He knows the midday sun is dangerous, but stopping means losing a day’s pay. When the heat makes him ill, he loses several days instead, and the next week he cannot afford to rest at all.
A composite, drawn from the evidence for each cycle. Not a real person.
A day in a heatwave
One day.
Every loop turning.
How the loops collide over a single day across Asia, from the Mekong Delta and Nepal’s plains to Dhaka, Jakarta, Bangkok and Chennai. The people here are illustrative composites, not real individuals; the loops they are caught in are on the map.
Live through a heatwave
Whose heatwave
will you follow?
Heat reaches people through their work, through their homes and bodies, and through the systems everyone depends on. Three short simulations, each built from the evidence, each ending with what could protect people at scale.
Care and health
A night in the heat
An older woman alone, a pregnant woman or a family with a baby, through a hot night and a clinic visit.
BeginCity systems
A city under strain
Power, water, clinics and trees through a five-day heatwave: choose what is in place, and see what holds.
BeginWork and income
A week in the heat
Follow one worker’s money through a heatwave week, build protection, then try to break it.
Begin
Who heat hits hardest
Same heatwave.
Different barriers.
Who is harmed depends on two things together: how exposed people are, and what stands between them and safety.
Age, gender, disability, illness, social identity, insecure tenure and unpaid care shape five questions.
Heat is not only a city problem. It reaches farms that depend on rain, coasts and riverbanks, and villages far from any clinic.
Weather, work and the person
How heat, work and the body add up
People in the same community may need different routes to the same outcome: livelihood security and dignity.
Also on the map: intimate partner violence rose about 4.5% with each 1 °C of yearly warmth across India, Nepal and Pakistan (Zhu et al., JAMA Psychiatry, 2023 (opens in a new tab)), and 466 million children now live where extremely hot days are at least twice as common as in the 1960s (UNICEF, 2024 (opens in a new tab)).
Act 2See how it connects
How does one harm lead to the next?
The guided view follows one vicious cycle, step by step. You can leave it at any moment and explore the whole map.
The web of extreme heat
One harm leads to the next.
Heat rarely does one thing. Here is the whole web, every link sourced, and the vicious cycles that keep it turning.
- Systems mapped
- 10
- Consequences mapped
- 90
- Vicious cycles
- 21
- Places to break them
- 33
- Institutions holding levers
- 14
This map is large, but the real web is larger. Every heatwave reveals links that aren’t drawn here yet.
Swipe up or down to scroll the page · drag sideways or pinch to explore · tap any dot
Why “wicked”?
No single cause.
No single owner.
No finish line.
In 1973 the planners Horst Rittel and Melvin Webber called some problems “wicked”: problems that resist a clean definition and have no final solution. Extreme heat is one of them.
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There is no single cause to fix
Heat arrives through land, bodies, cities and wallets at the same time, and each system pushes on the others.
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Every solution changes the problem
Air conditioning cools a room and heats the street, a textbook case of . Shifting work to cooler hours protects one worker and cuts another’s wages.
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The problem feeds itself
Dry soils, melting ice, burning forests and fossil-powered cooling all loop back to make the heat worse.
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Adaptation has limits
Places used to heat cope better with hot days, but a study of 2.7 million firms (OECD, 2024; opens in a new tab) found no adaptation to days above 40 °C, and heatwaves did more damage where it was already hot. Past a point, only cutting emissions helps.
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It lands unequally
The same heatwave is an inconvenience for some and a catastrophe for others: in a city flat or a rainfed field, on a coast or in a village hours from a clinic. The difference is protection, not temperature. See who heat hits hardest.
Breaking the cycles
21 vicious cycles.
33 ways to break them.
Each feeds itself, but every loop has weak links: points where one well-placed action stops the cycle from feeding itself. The strongest levers break several loops at once, and the pressure points are where many loops meet.
Pressure points
Where the most loops meet. Protect people here and several cycles weaken at once.
Levers that break more than one loop
“Well established” loops are widely documented. For loops marked “Evidence emerging”, each link is evidenced, but the full cycle has been studied less.
Act 3Where it lands
What is heat doing in your place?
The same heat lands differently in every city. Choose yours, see its heat today and its plans, and follow heat across Asia on the Atlas.
Heat right now
It is happening
today, in 12 Asian cities.
Is this climate change, and how hot is it indoors?
Want to see what this week’s forecast would switch on? Set your alert levels in step 4 of Plan a response (opens in the plan tab) and pick a city.
Your city
Pick a city.
See what heat is doing there.
Twelve cities, one view each: today’s heat and the week ahead, whether the city has a heat plan, the vicious cycles the evidence ties to it, who is hit hardest, and who is already at work. Every claim links to its source.
Heatwaves that shaped Asia
Twenty-eight years
of record heat.
Ten heatwaves across South and Southeast Asia, from Odisha in 1998 to the pre-monsoon heat of 2026: what happened, what it cost, and what changed afterwards. Tap a circle to read the story.
Print the one-pager: lessons from Asia’s heatwaves (printable page, opens in a new tab)
Act 4What helps
What can be done, and who holds it up?
Knowing is not the same as acting. These are the actions that help, the people who could hold each part, and why action sometimes stalls.
Why action stalls
Knowing is not
the same as acting.
Most places already know heat is dangerous. What holds them back is rarely a missing fact. It is usually one of these seven conditions. Each one shows how you can tell it is happening, and what has moved it elsewhere.
Check your own plan against them in step 4 of Plan a response (opens in the plan tab).
Who can act
Every loop runs
through an institution.
Heat becomes deadly where nobody acts. Each breaking point belongs to someone: a ministry, a city, an employer, an insurer, a funder, a community. Choose one to see the loops it can help break.
Bars show how many of the vicious cycles each institution’s levers can help break. No single institution can break them all, which is why the response has to be shared.
Find practical actions
What works, who does it,
and what keeps it working.
Pick a setting or start from a question: workplaces, homes, schools, clinics, markets and the decisions a city makes before summer. Each card answers what to do, who it protects, who acts, what it takes to run, the evidence and what could stop it.
Cooling options
Cool the places
where people are.
Choose a place. Each shows what to build or change, what keeps it working, a rough cost and the trap to avoid. Every claim links to its source, and where the evidence is thin, the card says so.
Deciding who acts and what it takes to run? Start with the practical actions (opens in a new tab), then come back here for options, costs and traps.
Four heats in a home
What cooling costs elsewhere in the region
Five traps that waste cooling money
What changes the result
Go deeper: free books and guides
Found in the reference lists of Nature-Based Solutions for Cities, and each one free to read online.
Paying for protection
Who pays, how it arrives,
and whether it lasts.
Plan a response
Turn the map
into a plan.
For a workshop or a team meeting. Six steps take you from who you are protecting to a plan you can run. The plan has a page of its own, so the map stays where you left it; anything you add here goes into the same plan.
- Where, and who are you protecting?
- Choose the actions
- Agree who leads, who pays, when it happens and how you will know
- Set the triggers and the warnings
- What could stop it?
- Check it against WHO’s eight core elements
Open your plan (opens in a new tab) Or start from a worked example: Ahmedabad, Thane, Tamil Nadu, Singapore, Dhaka (each opens in a new tab).
For NGOs and volunteer groups Make it work together: who has to say yes? A step-by-step simulation for coordinating protection in one place. Meet the people, find who decides what, build what needs to happen together, then run a hot week and see what reaches them. Open the simulation (opens in a new tab)Start here
Find your way in
Answer two questions and the site will suggest a short path, with how long each stop takes and what you will leave with.
Or browse the toolkit, in the order the tools build on each other
Act 5Together
What could we do together?
Where money has not yet reached, what nobody has measured yet, and the ways people are already joining in.
The heat network
Who is already
pulling the levers.
Organisations across Asia and the world already working on parts of this web. Choose a group, or open any lever on the map to see who is working on it.
Inclusion describes relevant published work. It does not imply partnership, affiliation or endorsement.
Where the gaps may be
How many organisations on this list work on a lever that acts on each loop. A low number shows a gap in this directory’s coverage, not proof that nobody is working on it.
Browse all 334 organisations
Download the whole list as a spreadsheet (CSV): name, side, group, what each does, the levers it works on and a link. For mapping who needs protection, who provides it and who connects them.
Go deeper. Libraries worth bookmarking. Almost every lever on the map also links to practical guides.
- Global Heat Health Information Network (opens in a new tab): guidance on heat warnings, heat action plans and heat at work
- Zurich Climate Resilience Alliance (opens in a new tab): studies and tools from programmes in Asia and beyond
- CEEW (opens in a new tab): district heat risk for all of India, and heat-health reports for India, Nepal, Bangladesh and Bhutan
- Wellcome (opens in a new tab): the research frontier on heat and health
- Beyond individual risk (opens in a new tab): why extreme heat demands a whole-system response
This list is a starting point, not a directory of everyone working on heat.
EpilogueHeld up together
No single cause. No single owner. No finish line.
That is why protection from extreme heat is held up together: by the people who live with it, the institutions that decide, and everyone who funds, studies and builds. Thank you for walking through it.
This month
Read the State of the field: where money moved, what the evidence added, and which questions grew in importance.
New evidence: the Lancet Countdown 2026, read for heat in Asia (opens in a new tab)
The UN calls for urgent action on extreme heat (opens in a new tab)
How this map works · Plain-language glossary · Corrections · Back to the beginning
How this map works
What the map shows,
and what it doesn’t.
An illustrative systems map
The links come from published evidence and expert judgment. Switching an action on shows which cycles it could help interrupt, not what it will achieve. Real effect depends on how many people it reaches, how well it is delivered and how long it lasts.
Three kinds of evidence
Evidence that one thing leads to another. Evidence that an action works. Evidence that a whole cycle runs as drawn. Well established means the whole cycle has been studied; Evidence emerging means each link has evidence but the full cycle has been studied less. The sources under “See the evidence” mostly show that links exist. Each one says what kind of source it is, where and how big it was, and what it cannot tell us. Where we draw a lesson the source does not state, it is marked Our reading, so you can tell our interpretation from the finding. Effects of heat depend on exposure, task and the person, so we avoid claims that hold everywhere.
Evidence labels
Practical action cards and cases carry a label saying what kind of evidence they cite. It describes the evidence, not how good the action is.
What works, and at what cost
This map focuses on how problems, institutions and actions connect. For ratings of how well interventions work, what they cost and how soon they help, see What Works Against Heat (opens in a new tab) , launched at the 2026 Global Heat Forum by the Global Heat Health Information Network and the University of Sydney.
Timing and the heat network
“How soon it works” tags are editorial judgments. Organisations are listed for relevant published work: inclusion does not imply partnership, affiliation or endorsement, and a low count shows a gap in this directory’s coverage, not proof that nobody is working on it.
Privacy
Visits are counted with GoatCounter (opens in a new tab), which uses no cookies, collects no personal data and does not follow you across sites. It also counts which tools get used, such as films watched and plans printed. What you type into a plan stays in your own browser.
Checked and updated
Last reviewed: 24 October 2026. Links and descriptions can go out of date as organisations and evidence move on.
Plain-language glossary
What does
wet-bulb mean?
39 terms that come up again and again in heat, explained in a sentence or two. Words underlined with dots across the site open the same explanations.
The web, link by link
Every consequence.
Every link.
The same map as a list, one system at a time. Every consequence and what it leads to.