What are the operating temperature limits for the TD-4279, and what happens if it is too hot or too cold?

The meter's operating condition is 10°C to 40°C (50°F to 104°F) at below 85% relative humidity (non-condensing). If the ambient temperature is outside this range, the error code E-t will appear on the display. You should move the meter and test strip into the acceptable temperature range and repeat the test. (Pages 29 and 31)