diff --git a/module3/exo1/influenza-like-illness-analysis.ipynb b/module3/exo1/influenza-like-illness-analysis.ipynb
index 342652219219c0f19d3768a734e4b55a1ee8c0f2..ed9aa2a62d0bde3033337250c0a4ef94b4fc80e8 100644
--- a/module3/exo1/influenza-like-illness-analysis.ipynb
+++ b/module3/exo1/influenza-like-illness-analysis.ipynb
@@ -59,6 +59,15 @@
     "The first line of the CSV file is a comment, which we ignore with `skip=1`."
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Data loading with local file check\n",
+    "\n",
+    "In order to protect us in case the Réseau Sentinelles Web server disappears or is modified, we make a local copy of this dataset that we store together with our analysis. Before loading the data, we check whether the file already exists locally. If not, it is downloaded from the Réseau Sentinelles Web server and saved as a CSV file. This approach ensures reproducibility and prevents unnecessary repeated downloads."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 7,