Help declaring a variable for temperature in thermistor--relay circuit

fixed?

#include <math.h>

int RelayHOT = 4;

double Thermister(int RawADC)
{
 double Temp;
 Temp = log(((10240000/RawADC) - 10000));
 Temp = 1 / (0.001129148 + (0.000234125 + (0.0000000876741 * Temp * Temp ))* Temp );
 Temp = Temp - 273.15;            // Convert Kelvin to Celcius
 return Temp;
}

void setup() 
{
 Serial.begin(115200);  
 pinMode(RelayHOT, OUTPUT);  
}

void loop() 
{
  float Temp = Thermister(analogRead(0));
  Serial.println(Temp,2);                      // print Celcius temp  with 2 decimals reading in serial monitor
 
  if (Temp < 27.5) digitalWrite(RelayHOT, HIGH);       //if the temperature is less than 27.5 C, turn on the relay which will turn on the light and increase temperature
  else if (Temp > 28.5) digitalWrite(RelayHOT, LOW);  //if the temperature is greater than 28.5 C, turn the bulb off because it is hot enough

  delay(5000);  // wait 5 seconds before sampling temperature again  - WHY?

}