The phones are normal phones but it's very likely they will be transmitting at their maximum power. Which is the power they're already being tested for.

However because it's only for texting for now, you won't be holding it too close to your head. And it will transmit for only a fraction of a second. Because radio energy drops really fast with distance it won't be a problem and will in fact be better than when you're having a phone call in bad coverage.