Phone thermometers pick up both the air temperature (ambient) and temperature of your phone and hands. These thermometers are designed to measure the temperature of your phone to throttle the CPU or power off the phone - not for measuring air temperature. Therefore, you should not rely on the thermometer in Trail Sense to give an accurate temperature reading, but rather a ballpark temperature reading. A better air temperature reading can be obtained by completely powering off your phone and letting it sit exposed to the air for several minutes (around 10 minutes is a good rule of thumb). When you power on the phone, heat will be generated, so you will need to quickly open the thermometer in Trail Sense for a more accurate reading.

# Calibrating

Given you are using your phone in the same way, the heat generated by the battery should be predictable. Therefore, you can perform a calibration step by doing the following:

1. Open the Barometer and Thermometer sensor settings in Trail Sense.
2. Place your phone in a cold temperature next to an actual thermometer (a refrigerator works well) and let sit for around 10 minutes
3. Once 10 minutes has elapsed, record the temperature shown in Trail Sense as the min phone temperature and the actual thermometer temperature as the min ambient temperature
4. Place your phone in a warm temperature next to an actual thermometer (a summer day or heated home works well) and let sit for around 10 minutes
5. Once 10 minutes has elapsed, record the temperature shown in Trail Sense as the max phone temperature and the actual thermometer temperature as the max ambient temperature
6. Your calibration should be complete, and you can see the calibrated temperature on the thermometer tool (in weather tab). For best results, use a wide temperature range for calibration

**Caution:** Refer to your phone's manual to identify the designed operating temperatures, do not exceed these when performing calibration.
