One way direction executed command

Idea is to make single direction command (not incremented type)
In this case temperature sensor triggers it between two thresholds and it remains activated in one direction only during rising or falling value
reason is to eliminate noise in relays and create some stable enviroment

#include "DHT.h"

#define DHTPIN A5    // what digital pin we're connected to

#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321

int controlPin = 6;

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  Serial.println("DHTxx test!");
  pinMode(controlPin, OUTPUT);
  dht.begin();
}

void loop() {
  // Wait a few seconds between measurements.
  delay(2000);

  // Reading temperature and humidity
  float h = dht.readHumidity();
  // Read temperature as Celsius
  float t = dht.readTemperature();

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");// add here later all outputs in off state
    return;                                           // safety feature
  }

  // Main code is not functional but only for demonstration of idea
  
  if (t <= 25.0)   // Idea is that it turns on lower threshold and it remains on till second
                   // threshold , but there is a catch it should be turned off while the sensor is cooled
                   // and when reaches first threshold turn back on where it loops forever like this
  digitalWrite(controlPin, HIGH);

  else if (t >= 26.0) digitalWrite(controlPin, LOW);

  // over here i would like to make it work in reverse for too high temperature or humidity
  if (t >= 29.0) digitalWrite(controlPin, HIGH);
  
  else if (t <= 28.0) digitalWrite(controlPin, LOW);
  
  Serial.print("Humidity: ");  //This is just for comparison with outside 
  Serial.print(h);             //more accurate hydrometer
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println(" *C ");
 
}

How about a state machine with three states, IDLE, HEATING and COOLING. Start in the idle state. If the temp is too warm go to the COOLING state which has one code and if the temp is too low go to the HEATING state and do the other code. In each state you can decide when to go back to IDLE.

I can’t get your sketch to compile.

sketch_nov04a:40: error: expected ';' before 'digitalWrite'
sketch_nov04a:45: error: expected ';' before 'digitalWrite'

You can’t put a boolean expression in an ‘else’ clause. It looks like you intended to use ‘else if’:

if (t <= 25.0)   // Idea is that it turns on lower threshold and it remains on till second
    // threshold , but there is a catch it should be turned off while the sensor is cooled
    // and when reaches first threshold turn back on where it loops forever like this
    digitalWrite(controlPin, HIGH);
  else if (t >= 26.0)
    digitalWrite(controlPin, LOW);

  // over here i would like to make it work in reverse for too high temperature or humidity
  if (t >= 29.0)
    digitalWrite(controlPin, HIGH);
  else if (t <= 28.0)
    digitalWrite(controlPin, LOW);

It says you’re missing some semicolons at the end of some lines. They don’t appear to be in the part you posted so you’ll have to look in the part you didn’t post. Its Damn hard for me to locte errors in partial code. Post the whole thing if you want help tracking them down.