I'm guessing you didn't work your way up to 3.8GHz and jumped straight in?
If you're going for an ambitious overclock (anything over 3.2GHz on a Q6600) you should take small steps to ensure stability.
Step one, achieving 3.2GHz stable. A few Q6600s can do this on stock voltages. You should try it, thoroughly stress test and increase the voltage using the smallest increment possible in your bios if you need to.
If you hit 3.2GHz fully stable on stock voltages, then increase the bus speed to around 366 for 3.3GHz. This will more than likely require a little more voltage. Make sure your RAM speed is kept as close to stock as possible, if you're a little over the rated speed, bump the voltage up slightly.
Just to compare, I'm running at 3.6GHz with 1.5v. Idle around 28-30C and peak temperature of 66C Prime95 large FFTs after 3 hours. Intel burn test further increases this temperate to 79C on maximum stress after 5 runs.