Fire alarm system by taking temperature value from DHT11 sen

int Buzz=A1;
#include <DHT.h>

#include "DHT.h"

#define DHTPIN A0     // what pin we're connected to

#define DHTTYPE DHT11   // DHT 11


DHT dht(DHTPIN, DHTTYPE);

void setup()
{
  Serial.begin(9600);
  for (int DigitalPin = 7; DigitalPin <= 9; DigitalPin++) 
 {
  pinMode(DigitalPin, OUTPUT);
  pinMode(Buzz,OUTPUT);
 }
  
dht.begin();
}
 
void loop()
{
  delay(1000);
  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
 // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  
  if (t<=22)
  {
  digitalWrite(7, HIGH);
  digitalWrite(8, LOW);
  digitalWrite(9, LOW);
  digitalWrite (Buzz,LOW);
  }
  else if (t>22)
  {
  digitalWrite(8, HIGH);
  digitalWrite(7, LOW);
  digitalWrite(9, LOW);
  }
  else if (t>=35)
  {
  digitalWrite(9, HIGH);
  digitalWrite(7, LOW);
  digitalWrite(8, LOW);
  digitalWrite(Buzz,HIGH);
  } 
  
}