diff --git a/stress-tests/Dockerfile b/stress-tests/Dockerfile
index 4f152f5..0fe639e 100644
--- a/stress-tests/Dockerfile
+++ b/stress-tests/Dockerfile
@@ -4,9 +4,9 @@ ARG IMAGE_TAG=2-bullseye
 FROM --platform=$IMAGE_ARCH torizon/debian:$IMAGE_TAG
 
 RUN apt-get update \
-    && apt-get install -y --no-install-recommends iperf3 rt-tests \
+    && apt-get install -y --no-install-recommends iperf3 rt-tests iputils-ping \
     && rm -rf /var/lib/apt/lists/*
 
-COPY / /
+COPY stress-tests.sh /stress-tests.sh
 
 CMD ["/stress-tests.sh"]
diff --git a/stress-tests/stress-tests.sh b/stress-tests/stress-tests.sh
index 286669c..3a5fe9b 100755
--- a/stress-tests/stress-tests.sh
+++ b/stress-tests/stress-tests.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+echo "Setting up stress tests..."
+
 # CPU load
 while true; do hackbench >/dev/null 2>&1; done &
 
@@ -9,9 +11,15 @@ while true; do find / -name a* >/dev/null 2>&1; done &
 
 # I/O load (USB read/write)
 if mount | grep /mnt/pendrive >/dev/null; then
-    cd /mnt/pendrive
-    tar -cf file.tar -C /var/log --exclude=lost+found -p .
-    while true; do rm -rf output; mkdir -p output; tar xfv file.tar -C output/ >/dev/null 2>&1; done &
+    if [ -e /mnt/pendrive/file.tar ]; then
+        cd /mnt/pendrive
+        tar -cf file.tar -C /var/log --exclude=lost+found -p .
+        while true; do rm -rf output; mkdir -p output; tar xfv file.tar -C output/ >/dev/null 2>&1; done &
+    else
+        echo "Warning: Archive file.tar not found in /mnt/pendrive. USB read/write stress test will not run."
+    fi
+else
+    echo "Warning: pendrive not mounted. USB read/write stress test will not run."
 fi
 
 # RTC read/write
@@ -19,7 +27,15 @@ while true; do hwclock >/dev/null 2>&1; sleep 0.1; done &
 while true; do hwclock -w >/dev/null 2>&1; sleep 0.1; done &
 
 # Network load
-while true; do iperf3 -c bouygues.iperf.fr -P 10 >/dev/null 2>&1; done
+if ! ping -q -c 1 -W 1 8.8.8.8 >/dev/null 2>&1; then
+    echo "Warning: could not ping 8.8.8.8. Internet may be unavailable to generate network load."
+fi
+while true; do
+    SERVERS="bouygues.iperf.fr speedtest.wtnet.de speedtest.iveloz.net.br iperf.scottlinux.com"
+    for s in $SERVERS; do
+        iperf3 -c $s -P 10 >/dev/null 2>&1
+    done
+done &
 
 echo "RT stress tests started successfully!"