Crews from Lythe and Whitby attended a fire to a sheep hut containing sheep and cattle in Mickleby, Saltburn-by-the-sea, North Yorkshire Fire and Rescue service said.
A farmer had extinguished the fire using a hosepipe prior to the arrival of crews shortly after 7am on Saturday, the service confirmed.
Crews used thermal imaging camera and farmer's hose pipe to dampen down and tackle the blaze.
Sadly, one lamb and ewe died in the fire, the fire service confirmed.
The cause of the fire is believed to be a fault in a heat lamp.