diff --git a/hiking_assistant/app.py b/hiking_assistant/app.py
index b9268bd..8fcad34 100644
--- a/hiking_assistant/app.py
+++ b/hiking_assistant/app.py
@@ -86,6 +86,10 @@ class HikingAssistant:
                         st.session_state.gradients = gradients
                         st.session_state.estimated_time = estimated_time
 
+                        # Show altitude sickness warning for first gpx loading
+                        if max_elevation >= self._config['app']['altitude_sickness']['elevation_threshold']:
+                            st.toast(self._config['app']['altitude_sickness']['warning_text'], icon=self._config['app']['altitude_sickness']['emoji'])
+
                 # Use cached data
                 total_distance = st.session_state.total_distance
                 elevation_gain = st.session_state.elevation_gain
diff --git a/hiking_assistant/assets/config.yaml b/hiking_assistant/assets/config.yaml
index a9597e7..afeef1d 100644
--- a/hiking_assistant/assets/config.yaml
+++ b/hiking_assistant/assets/config.yaml
@@ -2,5 +2,9 @@ app:
   page_title: 臺灣登山小幫手
   page_favicon_path: ./assets/favicon_compressed.jpg
   page_footer_text: ⚠️ 本服務提供之資訊僅供規劃參考，山區氣候瞬息萬變，請務必依據現場狀況與自身能力進行風險評估<br>Made with ❤️ by <a href="https://gitea.guineapig.love/deng">deng</a>
+  altitude_sickness:
+    elevation_threshold: 2100
+    warning_text: 此路線海拔較高，請留意高山症發生風險
+    emoji: 💊
   weather:
     forecast_days: 7
\ No newline at end of file