Here is my SHT21 and ds18b20 sensors

Thanks! Worked like a charm!

uint8_t interruptReturn;

void loop()  {
if (interruptReturn == 1){do this}
if (interruptReturn == MY_WAKE_UP_BY_TIMER){do that}
interruptReturn = sleep(INTERRUPT,CHANGE,SLEEP_TIME);
}

Next question: Is it possible to retrive remaining sleep time when waking up on interrupt so sensor could resume on time
left when it goes to sleep again?