Funny you should ask that. Just this minute I was using my cheap IR temperature reader to see how fast the FV heats up. It's so fast I'll do it again just for you. Just a sec... Okay, I should have said just 4 seconds. By 5 seconds this thing gives an error, which means it's over 300°C. Unfortunately, I'm certain it's reading the temperature of the heater underneath the screens, not the temperature at the screens which is where you really want to read. From experience, I'll say it reaches 250°C at the screen in not more than 6 seconds. You'll have to wait for someone with better equipment to get an accurate measure, but I'm sure I'm not off by more than a second. Disclosure: This thing cost me $15 reduced from $30 and I have been engaged in a lot of testing stuff with the FV. You have been caveated.