Came here looking for the same information. Pretty sure heat waves are in the game. I have a tek pyramid built into an adobe pyramid in the desert. I never overheat inside the pyramid because I assumed the adobe covering it stopped the heat. For the first time last night I was burning in my own tek building, I went to a separate room which is a pure adobe hallway in the same building, and I was a perfect temperature, went back into tek pyramid and I overheated again. I had Jerboa's in the room and did not notice any type of notification, but I believe this was certainly a heat wave. Hasn't happened all weekend, last night was the first time.