Low-Exposure Heat Routes
Enter a route and departure time on a hot day to get a lower-exposure travel plan with shade, water refill points, and cooling stops.
Delivery riders, outdoor workers, and people who have to pick up children may still be unable to cancel trips on a day with a heat alert. They enter an origin, destination, departure time, and required stops, and the product breaks the trip into specific segments for walking, cycling, waiting, and travel in a vehicle.
The map layers hourly feels-like temperature, sun direction, shaded segments, water refill points, and accessible air-conditioned spaces onto the itinerary. It suggests a lower-exposure departure plan and turns unavoidable high-risk segments into practical rest stops—for example, which mall to pause in for a few minutes or where to switch to the tree-shaded side of the street.
If users must leave as planned, the page highlights the segments where exposure rises fastest and what water and sun-protection items to bring. When risk exceeds a user-set threshold, it updates only the affected portion of the route. The first version supports walking, cycling, and public-transit connections. It does not provide medical judgments or replace local heat alerts.
Why now
US searches for “extreme heat watch” reached 20,000+, up 1,000%. Interest had already declined by July 24, but heat alerts create an immediate need for segment-by-segment heat-avoidance plans among people who cannot cancel their trips.
Target user
People who must still travel on a heat-alert day: delivery riders on deadline, outdoor shift workers, and those who need to pick up children or care for family members. They usually know the weather is dangerous but cannot simply cancel. Their planning need is most acute in the minutes before leaving and when exposure suddenly rises along part of the trip.
Minimal entry point
Start in a city with strong transit and public-facility data. Use the Google Routes API to retrieve walking, cycling, and transit segments; where transit does not support intermediate stops, calculate the boarding and alighting portions separately. S3 Read local heat alerts through the NWS Alerts API and cache their coverage areas and effective periods. S1 Build the shade layer with the ShadeMap toolkit, or precompute it from building footprints and sun position. S4 Include only verifiable public facilities as air-conditioned spaces and water refill points. The first release should offer two alternative routes and fixed rest stops, with no real-time health assessment.
Punching above its weight
Build shareable route cards around city heat alerts, showing segment-by-segment differences between the original and lower-exposure routes. Focus distribution on rider communities, parent groups, and outdoor-worker groups rather than broad weather content. Let users report unavailable water points, closed entrances, and actual shade conditions, then add verified reports back into local data. Rechecking frequently used routes whenever an alert is triggered can drive natural return visits.
Competitors & gaps
- Google MapsGoogle
- Google Maps already covers walking, cycling, and public-transit directions, and can combine some travel modes. It can calculate transit options by departure time and provide segment-level directions. S2S3 Its public help pages list duration, distance, price, travel preferences, and relevance among its ranking factors, but not heat exposure as a routing objective. S2 Users must therefore judge for themselves which segments are in direct sun, where they can refill water, and whether a waiting area has shade. The opportunity is not to replace basic navigation, but to add heat-exposure costs on top of existing routes and turn accessible places such as malls and libraries into explicit rest stops. The challenge is that opening hours and entry conditions at these locations change frequently. Without ongoing verification, Google Maps place search remains the more dependable general-purpose option.
- ShadeMapGoogle
- ShadeMap can simulate shadows from buildings, terrain, and trees for a chosen date and time, and display cumulative sunlight duration. S4 It is useful for seeing when a particular place will be shaded and provides browser-based sunlight-analysis tools. Its default building data comes from sources such as open maps, and shadow locations may be off by several meters. S4 Its core function remains shadow visualization, not end-to-end trip coordination. Users must assemble the shadow map, weather, route, and rest locations themselves. This product can condense those inputs into segment-level exposure and actionable stops. It can also account for cycling, waiting for transit, and in-vehicle travel rather than only walking routes. The real bar is to present shadow uncertainty candidly rather than depict a forecast’s limits as settled fact.
How it makes money
Offer a free basic route for individuals, with a monthly subscription. The free tier provides one plan per day; subscribers get saved routes, threshold alerts, and en-route recalculation. Later, charge delivery depots or outdoor teams per account, without making claims about employee health outcomes.
The case against
The central risk is not failing to calculate a route, but giving people false reassurance. Changes in building height, tree cover, and construction can distort shade estimates. Air-conditioned spaces may close temporarily, and water points may be unavailable. Detours add distance, and riders or caregivers may not be able to absorb the time cost. Weather changes and transit delays can also make precomputed plans obsolete quickly. Do not expand coverage unless the product can show data freshness, offer conservative alternatives, and correct errors quickly.