diff --git a/pyalarmdotcomajax/__init__.py b/pyalarmdotcomajax/__init__.py
index d10fc65..8e091e2 100644
--- a/pyalarmdotcomajax/__init__.py
+++ b/pyalarmdotcomajax/__init__.py
@@ -21,6 +21,7 @@
     BaseDevice,
     DeviceTypeSpecificData,
     TroubleCondition,
+    UserProfile,
 )
 from pyalarmdotcomajax.devices.partition import Partition
 from pyalarmdotcomajax.devices.registry import (
@@ -47,7 +48,7 @@
 )
 from pyalarmdotcomajax.websockets.client import WebSocketClient, WebSocketState
 
-__version__ = "0.5.7"
+__version__ = "0.5.8"
 
 log = logging.getLogger(__name__)
 
@@ -125,6 +126,10 @@ def __init__(
         self._user_email: str | None = None
         self._active_system_id: str | None = None
 
+        self._user_profile: UserProfile = {
+            "uses_celsius": False,
+        }
+
         self._ajax_headers = {
             "Accept": "application/vnd.api+json",
             "User-Agent": f"pyalarmdotcomajax/{__version__}",
@@ -136,10 +141,6 @@ def __init__(
             {}
         )  # Individual devices don't list their associated partitions. This map is used to retrieve partition id when each device is created.
 
-        self._installed_device_types: set[DeviceType] = (
-            set()
-        )  # List of device types that are present in a user's environment. We'll use this to cut down on the number of API calls made.
-
         self._trouble_conditions: dict = {}
 
         self.devices: DeviceRegistry = DeviceRegistry()
@@ -595,6 +596,12 @@ async def async_login(
             except KeyError:
                 self._keep_alive_url = self.KEEP_ALIVE_DEFAULT_URL
 
+            # Determines whether user uses celsius or fahrenheit. This is used for conversions within thermostats.
+            with contextlib.suppress(KeyError):
+                self._user_profile["uses_celsius"] = json_rsp["data"][0]["attributes"][
+                    "localizeTempUnitsToCelsius"
+                ]
+
             log.debug("*** START IDENTITY INFO ***")
             log.debug(f"Provider: {self._provider_name}")
             log.debug(f"User: {self._user_id} {self._user_email}")
@@ -822,6 +829,7 @@ async def _async_update__build_device(
         return device_class(
             id_=entity_id,
             raw_device_data=raw_device,
+            user_profile=self._user_profile,
             children=children,
             device_type_specific_data=device_type_specific_data.get(entity_id),
             send_action_callback=self.async_send_command,
diff --git a/pyalarmdotcomajax/devices/__init__.py b/pyalarmdotcomajax/devices/__init__.py
index 1868819..914f31a 100644
--- a/pyalarmdotcomajax/devices/__init__.py
+++ b/pyalarmdotcomajax/devices/__init__.py
@@ -75,6 +75,12 @@ class DeviceTypeSpecificData(TypedDict, total=False):
     raw_recent_images: list[dict]
 
 
+class UserProfile(TypedDict):
+    """Hold user profile fields required by devices."""
+
+    uses_celsius: bool
+
+
 class BaseDevice(ABC, CastingMixin):
     """Contains properties shared by all ADC devices."""
 
@@ -85,6 +91,7 @@ def __init__(
         config_change_callback: Callable | None,
         children: list[tuple[str, DeviceType]],
         raw_device_data: dict,
+        user_profile: UserProfile,
         device_type_specific_data: DeviceTypeSpecificData | None = None,
         trouble_conditions: list | None = None,
         partition_id: str | None = None,
@@ -99,6 +106,7 @@ def __init__(
         )
         self._settings: dict = settings if settings else {}
         self._partition_id: str | None = partition_id
+        self._user_profile: UserProfile = user_profile
 
         self.children = children
         self.trouble_conditions: list[TroubleCondition] = trouble_conditions if trouble_conditions else []
diff --git a/pyalarmdotcomajax/devices/thermostat.py b/pyalarmdotcomajax/devices/thermostat.py
index d0bfec8..ca3714b 100644
--- a/pyalarmdotcomajax/devices/thermostat.py
+++ b/pyalarmdotcomajax/devices/thermostat.py
@@ -100,6 +100,7 @@ class ThermostatAttributes(BaseDevice.DeviceAttributes):
         inferred_mode: (
             Thermostat.DeviceState | None
         )  # Indicates what thermostat is actually doing (cooling vs heating) if mode = auto.
+        uses_celsius: bool | None
         # Fan
         supports_fan_mode: bool | None
         supports_fan_indefinite: bool | None
@@ -167,6 +168,7 @@ def attributes(self) -> ThermostatAttributes:
             supports_schedules=self._get_bool("supportsSchedules"),
             supports_schedules_smart=self._get_bool("supportsSmartSchedules"),
             schedule_mode=self._get_special("scheduleMode", self.ScheduleMode),
+            uses_celsius=self._user_profile.get("uses_celsius"),
         )
 
     async def async_set_attribute(