diff --git a/tests/conftest.py b/tests/conftest.py
index 5d2ddbfe0..ae847a8b2 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,8 +1,11 @@
 """Shared pytest fixtures for the CodeCarbon test suite."""
 
+import threading
+
 import pytest
 
 from codecarbon.core.hardware_cache import clear_cache as clear_hardware_cache
+from codecarbon.external.scheduler import PeriodicScheduler
 
 
 @pytest.fixture(autouse=True)
@@ -20,3 +23,20 @@ def _reset_process_hardware_cache():
     yield
     clear_hardware_cache()
     detect_cpu_model.cache_clear()
+
+
+@pytest.fixture(autouse=True)
+def _stop_leaked_schedulers():
+    """Stop schedulers a test left running.
+
+    A tracker that is never stopped keeps re-arming a timer that then fires
+    into whatever test runs next. This is only a safety net: tests are still
+    expected to stop the trackers they start.
+    """
+    yield
+    for thread in threading.enumerate():
+        if not isinstance(thread, threading.Timer):
+            continue
+        scheduler = getattr(thread.function, "__self__", None)
+        if isinstance(scheduler, PeriodicScheduler):
+            scheduler.stop()
diff --git a/tests/test_emissions_tracker_flush.py b/tests/test_emissions_tracker_flush.py
index 63c394e76..6c568b374 100644
--- a/tests/test_emissions_tracker_flush.py
+++ b/tests/test_emissions_tracker_flush.py
@@ -24,16 +24,14 @@ class TestCarbonTrackerFlush(unittest.TestCase):
     def setUp(self) -> None:
         self.project_name = "project_TestCarbonTrackerFlush"
         self.emissions_file = "emissions-test-TestCarbonTrackerFlush.csv"
-        self.emissions_path = tempfile.gettempdir()
+        # A per-test directory, so that two tests counting rows in "their" file
+        # can never end up counting rows in the same one, see #1371.
+        self._temp_dir = tempfile.TemporaryDirectory()
+        self.addCleanup(self._temp_dir.cleanup)
+        self.emissions_path = self._temp_dir.name
         self.emissions_file_path = os.path.join(
             self.emissions_path, self.emissions_file
         )
-        if os.path.isfile(self.emissions_file_path):
-            os.remove(self.emissions_file_path)
-
-    def tearDown(self) -> None:
-        if os.path.isfile(self.emissions_file_path):
-            os.remove(self.emissions_file_path)
 
     def test_carbon_tracker_online_flush(self):
         tracker = EmissionsTracker(
diff --git a/tests/test_logging_output.py b/tests/test_logging_output.py
index a06fd7a5e..bdf10a52e 100644
--- a/tests/test_logging_output.py
+++ b/tests/test_logging_output.py
@@ -4,6 +4,7 @@
 import tempfile
 import time
 import unittest
+from pathlib import Path
 
 from codecarbon.emissions_tracker import (
     EmissionsTracker,
@@ -25,28 +26,42 @@ class TestCarbonTrackerFlush(unittest.TestCase):
     def setUp(self) -> None:
         self.project_name = "project_TestCarbonLoggingOutput"
         self.emissions_logfile = "emissions-test-TestCarbonLoggingOutput.log"
-        self.emissions_path = tempfile.gettempdir()
+        self._temp_dir = tempfile.TemporaryDirectory()
+        self.addCleanup(self._temp_dir.cleanup)
+        self.emissions_path = self._temp_dir.name
         self.emissions_file_path = os.path.join(
             self.emissions_path, self.emissions_logfile
         )
-        if os.path.isfile(self.emissions_file_path):
-            os.remove(self.emissions_file_path)
         self._test_logger = logging.getLogger(self.project_name)
         _channel = logging.FileHandler(self.emissions_file_path)
         self._test_logger.addHandler(_channel)
         self._test_logger.setLevel(logging.INFO)
         self.external_logger = LoggerOutput(self._test_logger, logging.INFO)
+        self._working_dir_csv = Path.cwd() / "emissions.csv"
+        self._working_dir_csv_size = self._read_working_dir_csv_size()
 
     def tearDown(self) -> None:
         for handler in self._test_logger.handlers[:]:
             self._test_logger.removeHandler(handler)
             handler.close()
-        if os.path.isfile(self.emissions_file_path):
-            os.remove(self.emissions_file_path)
+        # These tests only assert on the logger output, so they must not write
+        # the CSV in the working directory too. Sharing that file with the rest
+        # of the suite is what made them order dependent, see #1371.
+        self.assertEqual(
+            self._working_dir_csv_size,
+            self._read_working_dir_csv_size(),
+            "the tracker wrote to emissions.csv in the working directory",
+        )
+
+    def _read_working_dir_csv_size(self):
+        if not self._working_dir_csv.is_file():
+            return None
+        return self._working_dir_csv.stat().st_size
 
     def test_carbon_tracker_online_logging_output(self):
         tracker = EmissionsTracker(
             project_name=self.project_name,
+            save_to_file=False,
             save_to_logger=True,
             logging_logger=self.external_logger,
         )
@@ -64,6 +79,7 @@ def test_carbon_tracker_offline_logging_output(self):
         tracker = OfflineEmissionsTracker(
             project_name=self.project_name,
             country_iso_code="USA",
+            save_to_file=False,
             save_to_logger=True,
             logging_logger=self.external_logger,
         )
@@ -80,6 +96,7 @@ def test_carbon_tracker_offline_logging_output(self):
     def test_decorator_flush(self):
         @track_emissions(
             project_name=self.project_name,
+            save_to_file=False,
             save_to_logger=True,
             logging_logger=self.external_logger,
         )