This isn't true, the email they send is very clear that it's a sweepstakes based on enrolling in a program to raise your temperature during high heat momemts to help your fellow Texans to avoid brownouts.

In fact, the email begins by explaining how many heat deaths there are, how power outages affect vulnerable populations, and how if everyone could raise their temperatures 3 degrees during critical events we could avoid all of that.

And then a clear call to action to participate.