diff --git a/services/core/java/com/android/server/power/ThermalManagerService.java b/services/core/java/com/android/server/power/ThermalManagerService.java
index 96823c8ae9aba..f3785885e4ece 100644
--- a/services/core/java/com/android/server/power/ThermalManagerService.java
+++ b/services/core/java/com/android/server/power/ThermalManagerService.java
@@ -72,6 +72,12 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public class ThermalManagerService extends SystemService {
     private static final String TAG = ThermalManagerService.class.getSimpleName();
 
+    private static final boolean DEBUG = false;
+
+    /** Input range limits for getThermalHeadroom API */
+    public static final int MIN_FORECAST_SEC = 0;
+    public static final int MAX_FORECAST_SEC = 60;
+
     /** Lock to protect listen list. */
     private final Object mLock = new Object();
 
@@ -478,6 +484,13 @@ public class ThermalManagerService extends SystemService {
                 return Float.NaN;
             }
 
+            if (forecastSeconds < MIN_FORECAST_SEC || forecastSeconds > MAX_FORECAST_SEC) {
+                if (DEBUG) {
+                    Slog.d(TAG, "Invalid forecastSeconds: " + forecastSeconds);
+                }
+                return Float.NaN;
+            }
+
             return mTemperatureWatcher.getForecast(forecastSeconds);
         }
 
diff --git a/services/tests/servicestests/src/com/android/server/power/ThermalManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/power/ThermalManagerServiceTest.java
index 36e988f36577d..3848babdc9127 100644
--- a/services/tests/servicestests/src/com/android/server/power/ThermalManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/power/ThermalManagerServiceTest.java
@@ -381,6 +381,7 @@ public class ThermalManagerServiceTest {
         assertEquals(0, Arrays.asList(mService.mService.getCurrentTemperaturesWithType(
                         Temperature.TYPE_SKIN)).size());
         assertEquals(Temperature.THROTTLING_NONE, mService.mService.getCurrentThermalStatus());
+        assertTrue(Float.isNaN(mService.mService.getThermalHeadroom(0)));
     }
 
     @Test
@@ -396,6 +397,14 @@ public class ThermalManagerServiceTest {
                         CoolingDevice.TYPE_CPU)));
     }
 
+    @Test
+    public void testGetThermalHeadroomInputRange() throws RemoteException {
+        assertTrue(Float.isNaN(mService.mService.getThermalHeadroom(
+                ThermalManagerService.MIN_FORECAST_SEC - 1)));
+        assertTrue(Float.isNaN(mService.mService.getThermalHeadroom(
+                ThermalManagerService.MAX_FORECAST_SEC + 1)));
+    }
+
     @Test
     public void testTemperatureWatcherUpdateSevereThresholds() throws RemoteException {
         ThermalManagerService.TemperatureWatcher watcher = mService.mTemperatureWatcher;