Counting and taking temperatures for You

#include <LiquidCrystal.h>
#include <Wire.h>
#include <Adafruit_MLX90614.h>
int in = 15;// Analog Pin A1 Signal for Sensor 
int inpr = 16;// Analog Pin A2 Power for Sensor
int out = 14;// Analog Pin A0 Signal for Sensor
int outpr = 17;// Analog Pin A3 Power for Sensor
int ppl = 0;// declare ppl false
int buzzer = 9;
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
bool pplin = 0;// false 
bool pplout = 0;// false
int temp = 0;// temp starting point 
const float alert_temp = 38.0;// alarm setpoint
Adafruit_MLX90614 mlx = Adafruit_MLX90614();
void setup() {
  Serial.begin(9600);
  Serial.println("B00123587 Project");  /// display on serial monitor
  pinMode(15, INPUT);// Analog Pin A1 Signal for Sensor
  pinMode(14, INPUT);// Analog Pin A0 Signal for Sensor
  pinMode(16, OUTPUT);// Analog Pin A2 Power for Sensor
  pinMode(17, OUTPUT);// Analog Pin A3 Power for Sensor
  pinMode(6, OUTPUT);//LED entry
  pinMode(7, OUTPUT);//LED no entry
  lcd.begin(16, 2);
  mlx.begin();  
}

void loop() {
  digitalWrite(outpr, HIGH);// Analog Pin A2 Power for Sensor High
  digitalWrite(inpr, HIGH);// Analog Pin A3 Power for Sensor High
  pplin = digitalRead(in); //people in
  pplout = digitalRead(out);//people out
  if (pplin == 1){ // pplin true 
    ppl--;//changes value
    delay(500);
  }
  else if (pplout == 1){//pplout true
    ppl++ ;//changes value
    delay(500);
  }
  ppl = constrain(ppl, 0, 50);//sensor range
  lcd.setCursor(0, 0);//what LCD has to do
  lcd.print("People In:");
  lcd.setCursor(11, 0);//what LCD has to do
  lcd.print(ppl);
  if (ppl >= 5){//cut off point for entry
     lcd.setCursor(0, 1);//what LCD has to do
     lcd.print("PLEASE   WAIT");
    digitalWrite(6, LOW);//Green LED off
    digitalWrite(7, HIGH);//Red LED on
    }
    if (ppl >=6){//pplout true
    tone(buzzer,450);///HZ
     delay(500);
     noTone(buzzer);
     delay(500);
    
    }
    
  if (ppl <= 4){// less than 4 ok for entry
     lcd.setCursor(0, 1);// What LCD has to do
     lcd.print("Safe to enter");
    digitalWrite(7, LOW);//Green LED on
    digitalWrite(6, HIGH);// Red LED off
    noTone(buzzer); ////
     delay(500);
  }
   lcd.setCursor(14,0);// display section of temperature 
  Serial.print(mlx.readObjectTempC());//read the sensor
  Serial.println("*C");// print in degrees celsius
  lcd.print(mlx.readObjectTempC());// print temp on screen
  Serial.println();
  delay(500);
  temp = (mlx.readObjectTempC());
   if (temp >= alert_temp){/// buzzer alarm if greater than 38 degrees 
   tone(buzzer,450);///HZ
     delay(500);
     noTone(buzzer);
     delay(2000);
   } 
}