Contactless Thermometer

/**
   ICC. Temperature Module
   I2C for LCD 16x2
   MLX90614 Temperature Sensor, 3.3v
   A4 = SDA
   A5 = SCL
   Hardware Connections:
    Arduino | HC-SR04
    -------------------
      5V    |   VCC
      7     |   Trig
      6     |   Echo
      GND   |   GND
*/
#include <Wire.h>
#include <Adafruit_MLX90614.h>
#include <LiquidCrystal_I2C.h>

//I2C pins declaration
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);

// Pins
const int TRIG_PIN = 7;
const int ECHO_PIN = 6;
const int buzzer = 8;


// Anything over 400 cm (23200 us pulse) is "out of range"
const unsigned int MAX_DIST = 23200;
Adafruit_MLX90614 mlx = Adafruit_MLX90614();

void setup() {

  // The Trigger pin will tell the sensor to range find
  pinMode(TRIG_PIN, OUTPUT);
  digitalWrite(TRIG_PIN, LOW);

  //Set Echo pin as input to measure the duration of 
  //pulses coming back from the distance sensor
  pinMode(ECHO_PIN, INPUT);
  pinMode(buzzer, OUTPUT);

  // We'll use the serial monitor to view the sensor output
  Serial.begin(9600);
  mlx.begin();

  //LCD Display Configuration
  lcd.begin(16,2);//Defining 16 columns and 2 rows of lcd display
  lcd.backlight();//To Power ON the back light
  //lcd.backlight();// To Power OFF the back light
}

void loop() {

  unsigned long t1;
  unsigned long t2;
  unsigned long pulse_width;
  float cm;
  float inches;
      int v;
    float w;

  // Hold the trigger pin high for at least 10 us
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Wait for pulse on echo pin
  while ( digitalRead(ECHO_PIN) == 0 );

  // Measure how long the echo pin was held high (pulse width)
  // Note: the micros() counter will overflow after ~70 min
  t1 = micros();
  while ( digitalRead(ECHO_PIN) == 1);
  t2 = micros();
  pulse_width = t2 - t1;

  // Calculate distance in centimeters and inches. The constants
  // are found in the datasheet, and calculated from the assumed speed
  //of sound in air at sea level (~340 m/s).
  cm = pulse_width / 58.0;
  inches = pulse_width / 148.0;
  lcd.setCursor(0,0);
  lcd.print("Welcome to MOU");
  // Print out results
  if ( pulse_width > MAX_DIST ) {
    Serial.println("Out of range");
  } 
  else {
//    Serial.print(cm);
//    Serial.print(" cm \t");
//    Serial.print(inches);
//    Serial.println(" in");
  if (cm <= 10)
  {
    if (mlx.readObjectTempC() >= 37.5)
    {
     lcd.clear();
     lcd.setCursor(0,1);
     lcd.print("Temp   ");
     lcd.print(mlx.readObjectTempC());
     lcd.print(" C");
     Serial.println((String)"Detected:" + mlx.readObjectTempC() + " C " + " Exit Now");
     lcd.setCursor(4,0);
     lcd.print("Exit now");
     tone(buzzer, 2000);
     delay(300);
     noTone(buzzer);
    }
    if (mlx.readObjectTempC() < 37.5)
    {
    lcd.setCursor(0,1);
    lcd.print("Temp   ");
    lcd.print(mlx.readObjectTempC());
    lcd.print(" C");
    tone(buzzer, 1000);
    delay(100);
    noTone(buzzer);
    Serial.println((String)"Detected:" + mlx.readObjectTempC() + "C");
  }
  }
  delay(3000);
  lcd.clear();
}
}