A Heat Generator is an Object commonly found in the Corpus Ice Planet Tile Sets. They are scattered throughout outdoor sections of the map openly exposed to the planet's atmosphere, which prevent shield degeneration if players are within their 15m operating radius.
Although Heat Generators offer protection from the cold, they can be destroyed by weapons fire from both enemies and Tenno alike, and are especially vulnerable to area-of-effect attacks (e.g. 
Nova's 
Molecular Prime) and explosives. Caution is advised when fighting outdoors.