Plan patrols around heat, cold, lightning and bad air, hour by hour, a week ahead.
Heat stress (WBGT), wind chill, a lightning signal and particulates for 50 towns on the western and eastern land borders, the coasts and the high passes, with US Army TB MED 507 work/rest and water guidance and the safest window for each task. For unit commanders and medical officers; a free public version covers the same towns.
The National Centre for Disease Control puts the death rate of heat stroke at 40 to 64 % and calls it preventable (NCDC, 2024): prevention means timing work, rest and water to the conditions. The people most exposed work outdoors on the Rajasthan and Punjab border, along humid river and coastal belts, and at high passes where the risk turns to frostbite.
The standard tool, WBGT, is measured on site, often once for a whole station. TB MED 507 found that two sites 13 km apart disagreed by one or two heat categories in 38 % of paired readings. Planners need a view of the next days, hour by hour, for every post's nearest town, and a measured reading before the task starts.
- Hourly WBGT for 7 days at 50 towns, graded into TB MED 507 heat categories (white, green, yellow, red, black flags), with work/rest cycles and water for easy, moderate, heavy and very heavy work.
- Wind chill and frostbite risk (Environment and Climate Change Canada bands) for Leh, Kargil, Drass, Kaza, Munsiyari, Gangtok, Lachung and Tawang, and every other town.
- A lightning signal from CAPE and rain, and a particulate index on India's CPCB scale.
- The safest patrol windows each day, and a planner that recomputes on the device for full shade, heavy protective clothing, high-risk timed events and a safety margin, with a water plan and a plan you can paste into a message.
- A free public page with plain-language heat and cold advice by town, heat stroke first aid from NCDC, and Hindi lines.
- FetchTwo batched requests return 7 days of hourly weather and 4.5 days of PM2.5, PM10 and dust for all 50 towns.
- ModelThe globe and wet-wick heat balances of Liljegren et al. (2008) give WBGT each hour from temperature, humidity, pressure, wind and sun.
- GradeTB MED 507 categories and work/rest, NWS heat index, ECCC wind chill, CAPE × rain, CPCB breakpoints.
- PlanEvery start time is ranked by its worst hour of heat, lightning and cold, daylight aware.
- PublishJSON exports with provenance; the browser mirror of the maths reruns the plan for shade and clothing.
Validated against published values: Stull's wet-bulb example, NWS heat index and ECCC wind chill charts, the CPCB breakpoint table, a closed globe energy balance, and a test that the browser and pipeline agree to 0.006 °C. Full methods (console sign-in) and public page.
TB MED 507 (2022) Table 3-2, minutes of work per hour for heat-acclimatised personnel; water rises from 0.47 to 0.95 L an hour. Never more than 1.4 L an hour or 11.4 L a day.
| WBGT | Category | Easy | Moderate | Heavy | Very heavy |
|---|---|---|---|---|---|
| 25.6–27.8 °C | Cat 1 | No limit | No limit | 40/20 | 20/40 |
| 27.8–29.4 °C | Cat 2 | No limit | No limit | 30/30 | 15/45 |
| 29.4–31.1 °C | Cat 3 | No limit | No limit | 30/30 | 10/50 |
| 31.1–32.2 °C | Cat 4 | No limit | 50/10 | 20/40 | 10/50 |
| above 32.2 °C | Cat 5 | No limit | 20/40 | 15/45 | 10/50 |
| Source | What | Licence | Status |
|---|---|---|---|
| Open-Meteo Forecast API | Hourly temperature, humidity, wind, pressure, global, direct and diffuse sun, CAPE, rain, UV, visibility | CC BY 4.0 | Live |
| Open-Meteo Air Quality API (CAMS) | PM2.5, PM10 and dust, about 4.5 days ahead | CC BY 4.0 | Live |
| US Army TB MED 507 (2022) | Heat categories, work/rest, water, clothing adjustment | Public release | Reference |
| NCDC, Emergency Cooling (2024) | Heat stroke first aid on the public page | Government of India | Reference |
| Trinetra reference towns | 42 frontier towns and 8 high-altitude towns, public centroids | Trinetra | Reference |
- Unit and post commanders choose patrol and work hours, and see which days need a changed plan.
- Medical officers set work/rest and water, prepare cooling for heat casualties, and watch frostbite risk at the passes.
- Training officers time high-risk events such as timed marches to the coolest hours, using the sports categories TB MED 507 prescribes for them.
- District administrations and the public use the free heat and cold page.
- Places and conditions only: no data about any person, and only public town centroids. Post locations, if a unit adds them, stay on its own servers.
- Every forecast states its source, time and expected error, and that it is advisory. The pages tell users to measure WBGT on site and to follow IMD, NDMA and their medical officer.
- The public page has no account and no tracking; it remembers your town only on your own device.
- The method is published, with tests against reference values that anyone can run.
- Forecast WBGT is typically within 1 to 2 °C; TB MED 507 itself says WBGT cannot be accurately forecast. One category either way is common.
- Model grids of 10 to 25 km cannot see a dune, a river bank or a tin roof; near-calm hours are the least certain.
- The tables assume heat-acclimatised, fit, rested personnel in a standard uniform.
- The lightning signal is a heuristic, and the particulate index is not the official AQI.
- The free weather API is for non-commercial use; deployment needs a subscription or a self-hosted instance.
Pilot with a unit or a district: we add your posts privately on your servers, calibrate against your WBGT monitors for one season, and send the day's plan to your control room. contact@trinetra.in