diff --git a/apiclient/client.py b/apiclient/client.py
index 0234604..e60a8db 100644
--- a/apiclient/client.py
+++ b/apiclient/client.py
@@ -7,6 +7,7 @@ from requests_oauthlib import OAuth2Session
 
 def api_client(call_dict, verify_cert=False, oauth=False):
 
+    method = call_dict["method"]
     url = call_dict["url"]
     headers = call_dict["headers"]
     body = call_dict["body"]
@@ -15,8 +16,7 @@ def api_client(call_dict, verify_cert=False, oauth=False):
         client = OAuth2Session(token=call_dict["token"])
     else:
         client = requests.Session()
-
-    method = call_dict["method"]
+    client.cookies.clear()
 
     try:
         if method == 'GET':
diff --git a/apiclient/config.py b/apiclient/config.py
index 57cbc45..5ed9af4 100644
--- a/apiclient/config.py
+++ b/apiclient/config.py
@@ -1,27 +1,36 @@
 import os
-from dotenv import load_dotenv
+from dotenv import dotenv_values
 from types import MappingProxyType
 
 
 PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 
+# Dict to hold values from dotenv files; keys are filenames, values are dictionaries of env vars
+_dotenv_values = {}
 
-def get_cfg(env='qa'):
+
+def get_cfg(env='qa', force_refresh=False):
     environment_name = os.getenv('ENV_NAME', env)
     dotenv_path = os.path.join(PROJECT_ROOT, f'.env.{environment_name}')
     if not os.path.exists(dotenv_path):
         raise FileNotFoundError(f"{dotenv_path} does not exist")
-    load_dotenv(dotenv_path)
+
+    if dotenv_path not in _dotenv_values or force_refresh:
+        # Load the env vars from the dotenv file and store them in the _dotenv_values dict
+        _dotenv_values[dotenv_path] = dotenv_values(dotenv_path)
+
+    # Now, we're sure that _dotenv_values[dotenv_path] contains up-to-date env vars from dotenv_path
+    dotenv_vars = _dotenv_values[dotenv_path]
 
     config_dict = {
-        'client_id': os.getenv('CLIENT_ID'),
-        'client_secret': os.getenv('CLIENT_SECRET'),
-        'token_url': os.getenv('TOKEN_FETCH_URL'),
-        'login': os.getenv('LOGIN'),
-        'password': os.getenv('PASSWORD'),
-        'audience': os.getenv('AUDIENCE'),
-        'scopes': os.getenv('SCOPES', '').split(','),
-        'api_url': os.getenv('API_URL')
+        'client_id': dotenv_vars.get('CLIENT_ID'),
+        'client_secret': dotenv_vars.get('CLIENT_SECRET'),
+        'token_url': dotenv_vars.get('TOKEN_FETCH_URL'),
+        'login': dotenv_vars.get('LOGIN'),
+        'password': dotenv_vars.get('PASSWORD'),
+        'audience': dotenv_vars.get('AUDIENCE'),
+        'scopes': dotenv_vars.get('SCOPES', '').split(','),
+        'api_url': dotenv_vars.get('API_URL')
     }
     config = MappingProxyType(config_dict)  # immutable dict
     return config
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..4872797
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,20 @@
+import pytest
+import requests
+from requests_oauthlib import OAuth2Session
+
+
+@pytest.fixture(scope="function")
+def reset_open_session():
+    open_session = requests.Session()
+    open_session.cookies.clear()
+    yield open_session
+    open_session.close()
+
+
+@pytest.fixture(scope="function")
+def reset_oauth_session():
+    oauth_session = OAuth2Session()
+    oauth_session.cookies.clear()
+    yield oauth_session
+    oauth_session.close()
+
diff --git a/tests/oauth_service/conftest.py b/tests/oauth_service/conftest.py
index 75e01d4..6fa7b65 100644
--- a/tests/oauth_service/conftest.py
+++ b/tests/oauth_service/conftest.py
@@ -2,14 +2,14 @@ import pytest
 from apiclient.config import get_cfg
 from apiclient.oauth_helper import get_legacy_token
 
-ENV = 'qa'  # This would be set in an actual OS env var on the execution platform
-CFG = get_cfg(ENV)  # needed for the token, and the full api url
 
+ENV = 'qa'
+CFG = get_cfg(ENV, force_refresh=True)
 application_json = {'Content-Type': 'application/json'}
 
 
 @pytest.fixture
-def role_get_call():
+def role_get_call(reset_oauth_session):
     token = get_legacy_token(ENV)
     api_call = {
         "token": token,
@@ -22,7 +22,7 @@ def role_get_call():
 
 
 @pytest.fixture
-def acms_redaction_get_call():
+def acms_redaction_get_call(reset_oauth_session):
     token = get_legacy_token(ENV)
     api_call = {
         "token": token,
@@ -35,7 +35,7 @@ def acms_redaction_get_call():
 
 
 @pytest.fixture
-def client_applications_get_call():
+def client_applications_get_call(reset_oauth_session):
     token = get_legacy_token(ENV)
     api_call = {
         "token": token,
@@ -48,7 +48,7 @@ def client_applications_get_call():
 
 
 @pytest.fixture
-def endpoint_get_call():
+def endpoint_get_call(reset_oauth_session):
     token = get_legacy_token(ENV)
     api_call = {
         "token": token,
@@ -63,7 +63,7 @@ def endpoint_get_call():
 
 
 @pytest.fixture
-def redaction_type_get_call():
+def redaction_type_get_call(reset_oauth_session):
     token = get_legacy_token(ENV)
     api_call = {
         "token": token,
diff --git a/tests/oauth_service/test_datadelivery.py b/tests/oauth_service/test_datadelivery.py
index ddade1c..6450514 100644
--- a/tests/oauth_service/test_datadelivery.py
+++ b/tests/oauth_service/test_datadelivery.py
@@ -1,7 +1,7 @@
 import json
 import pytest
 from apiclient.client import api_client
-from oauth_service.helpers import get_expected_response
+from tests.oauth_service.helpers import get_expected_response
 
 
 ####
@@ -14,7 +14,7 @@ from oauth_service.helpers import get_expected_response
 @pytest.mark.role
 def test_datadelivery_role_get(request, role_get_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(role_get_call)
+    actual_response = api_client(role_get_call, oauth=True)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
 
 
@@ -22,7 +22,7 @@ def test_datadelivery_role_get(request, role_get_call):
 @pytest.mark.redaction
 def test_datadelivery_acms_redaction_get(request, acms_redaction_get_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(acms_redaction_get_call)
+    actual_response = api_client(acms_redaction_get_call, oauth=True)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
 
 
@@ -30,7 +30,7 @@ def test_datadelivery_acms_redaction_get(request, acms_redaction_get_call):
 @pytest.mark.client_application
 def test_datadelivery_client_applications_get(request, client_applications_get_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(client_applications_get_call)
+    actual_response = api_client(client_applications_get_call, oauth=True)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
 
 
@@ -38,7 +38,7 @@ def test_datadelivery_client_applications_get(request, client_applications_get_c
 @pytest.mark.endpoint
 def test_datadelivery_endpoint_get(request, endpoint_get_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(endpoint_get_call)
+    actual_response = api_client(endpoint_get_call, oauth=True)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
 
 
@@ -46,5 +46,5 @@ def test_datadelivery_endpoint_get(request, endpoint_get_call):
 @pytest.mark.redaction
 def test_datadelivery_redaction_type_get(request, redaction_type_get_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(redaction_type_get_call)
+    actual_response = api_client(redaction_type_get_call, oauth=True)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
\ No newline at end of file
diff --git a/tests/open_service/conftest.py b/tests/open_service/conftest.py
index 0c893ea..597ee69 100644
--- a/tests/open_service/conftest.py
+++ b/tests/open_service/conftest.py
@@ -1,29 +1,27 @@
 import pytest
 from apiclient.config import get_cfg
 
-ENV = 'gw'  # This would be set in an actual OS env var on the execution platform
-CFG = get_cfg(ENV)  # needed for the token, and the full api url
 
-application_json = {'Content-Type': 'application/json'}
+CFG = get_cfg('gw', force_refresh=True)
 
 
 @pytest.fixture
-def get_creatures_call():
+def get_creatures_call(reset_open_session):
     api_call = {
         "method": "GET",
         "url": CFG["api_url"] + '/rules/creature',
-        "headers": application_json,
+        "headers": {},
         "body": {}
     }
     return api_call
 
 
 @pytest.fixture
-def get_creature_call():
+def get_creature_call(reset_open_session):
     api_call = {
         "method": "GET",
         "url": CFG["api_url"] + '/rules/creature',
-        "headers": application_json,
+        "headers": {},
         "body": {"creature": "badder"}
     }
     return api_call
diff --git a/tests/open_service/test_gammaworld.py b/tests/open_service/test_gammaworld.py
index beab308..8dd56bd 100644
--- a/tests/open_service/test_gammaworld.py
+++ b/tests/open_service/test_gammaworld.py
@@ -2,18 +2,18 @@ import json
 import pytest
 
 from apiclient.client import api_client
-from open_service.helpers import get_expected_response
+from tests.open_service.helpers import get_expected_response
 
 
 @pytest.mark.rules
 def test_get_creatures(request, get_creatures_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(get_creatures_call)
+    actual_response = api_client(get_creatures_call, oauth=False)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
 
 
 @pytest.mark.rules
 def test_get_creature(request, get_creature_call):
     expected_response = get_expected_response(request.node.name)
-    actual_response = api_client(get_creature_call)
+    actual_response = api_client(get_creature_call, oauth=False)
     assert json.dumps(actual_response, indent=4) == json.dumps(expected_response, indent=4)
\ No newline at end of file