diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index b34636004..1bd9c82cd 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -2096,7 +2096,9 @@ not affect the color.
 
 At far zoom (camera above ~3,000 km) the layer drapes a Snap Map–style
 heatmap instead of individual markers: the shown detections are binned on a
-global 2048 × 1024 grid, each weighted `1 + log10(1 + FRP)`, Gaussian-blurred,
+global 2048 × 1024 grid, each weighted by its FRP in megawatts (so heat is
+radiated power, and raising the FRP slider does not dim areas where strong fires
+burn), Gaussian-blurred,
 normalized on a log scale against the 99.5th percentile and mapped from blue
 through cyan, green, yellow and orange to red. Nothing is painted where
 nothing burns (`src/data/firmsHeatRaster.js`). It is one full-globe imagery
diff --git a/src/data/firmsHeatRaster.js b/src/data/firmsHeatRaster.js
index 52a020671..516c7676f 100644
--- a/src/data/firmsHeatRaster.js
+++ b/src/data/firmsHeatRaster.js
@@ -35,8 +35,17 @@ export function heatColorAt(t) {
   ];
 }
 
+/** Weight of a detection with no or zero FRP, in megawatts. */
+export const HEAT_MIN_WEIGHT_MW = 0.5;
+
+/**
+ * Heat is radiated power, not a head count: each detection adds its FRP in
+ * megawatts. Weak fires carry little power, so raising the minimum-FRP slider
+ * removes most detections without dimming the areas where strong fires burn
+ * (a count-based heat collapsed there and the hot spots faded).
+ */
 const defaultWeight = (fire) =>
-  1 + Math.log10(1 + Math.max(0, Number(fire.frp) || 0));
+  Math.max(HEAT_MIN_WEIGHT_MW, Number(fire.frp) || 0);
 
 export function binFires(fires, { width, height, weight = defaultWeight }) {
   const grid = new Float32Array(width * height);
diff --git a/src/data/firmsHeatRaster.test.mjs b/src/data/firmsHeatRaster.test.mjs
index 704c83427..2b51785e6 100644
--- a/src/data/firmsHeatRaster.test.mjs
+++ b/src/data/firmsHeatRaster.test.mjs
@@ -1,6 +1,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import {
+  HEAT_MIN_WEIGHT_MW,
   HEAT_PALETTE,
   heatColorAt,
   binFires,
@@ -23,7 +24,7 @@ test('palette runs cold to hot and starts fully transparent', () => {
 });
 
 test('binFires drops each detection into its equirectangular pixel', () => {
-  const grid = binFires([fire(89.9, -179.9, 0), fire(-89.9, 179.9, 0)], {
+  const grid = binFires([fire(89.9, -179.9, 1), fire(-89.9, 179.9, 1)], {
     width: 4,
     height: 2,
   });
@@ -35,9 +36,33 @@ test('binFires drops each detection into its equirectangular pixel', () => {
   );
 });
 
-test('binFires weights strong fires slightly more', () => {
-  const grid = binFires([fire(0.1, 0.1, 999)], { width: 4, height: 2 });
-  assert.ok(grid[2] > 3 && grid[2] < 5, String(grid[2]));
+test('binFires weights each detection by its radiative power', () => {
+  const grid = binFires(
+    [fire(0.1, 0.1, 250), fire(0.2, 0.2, 0), fire(0.3, 0.3, Number.NaN)],
+    { width: 4, height: 2 },
+  );
+  assert.equal(grid[2], 250 + 2 * HEAT_MIN_WEIGHT_MW);
+});
+
+test('filtering out weak fires keeps a strong fire hot', () => {
+  const strong = fire(0.1, 0.1, 300);
+  const weak = Array.from({ length: 40 }, () => fire(0.1, 0.1, 2));
+  const reference = Array.from({ length: 10 }, () => fire(20.1, 20.1, 100));
+  const options = { width: 360, height: 180, sigmaPx: 2 };
+  const pixel = ((90 - 0.1) | 0) * 360 + ((0.1 + 180) | 0);
+  const red = (r) => r.rgba[pixel * 4];
+  const alpha = (r) => r.rgba[pixel * 4 + 3];
+  const unfiltered = buildHeatRaster([strong, ...weak, ...reference], options);
+  const filtered = buildHeatRaster([strong, ...reference], options);
+  assert.ok(alpha(filtered) > 0);
+  assert.ok(
+    alpha(filtered) >= alpha(unfiltered) * 0.9,
+    `alpha ${alpha(unfiltered)} -> ${alpha(filtered)}`,
+  );
+  assert.ok(
+    red(filtered) >= red(unfiltered) * 0.9,
+    `red ${red(unfiltered)} -> ${red(filtered)}`,
+  );
 });
 
 test('blurGaussian keeps mass and wraps across the antimeridian', () => {