Sensirion SHT31x Sensor

I am using a Sensirion Humidity SHT-31x sensor with an Arduino WiFi Rev2.

Adafruit Sensirion SHT31-D [Temperature & Humidity Sensor] : ID 2857 : $13.95 : Adafruit Industries, Unique & fun DIY electronics and kits

According to the datasheet, the sensor can be powered via 5V or 3.3V pin on the Arduino. The sensor works fine when Vin is connected to 3.3V, but if you changed the voltage supply to 5V, the LCD is reading that the temperature of the sensor is 210F, which is inaccurate. Any ideas why the sensor would supposedly be heating up due to the change in supply voltage? The SDA and SCL lines on the sensor I2C breakout board are connected straight to the SDA and SCL pins of the Arduino.

I use the SHT-31 sensor on my own boards and drive it by 5V. I cannot see any wrong temperature reading. So it's either your wiring or your code that is producing that wrong reading, both we don't know in detail.

BTW: You shouldn't power the sensor by 3.3V and connect the IO lines to 5V (as you did), that's outside the datasheet specs.