A pair of tens is a hand you should stand on.
A total of 20 can only be beat by a dealer 21. And even if you make this huge longshot, the best you can do is a push. But since this is the only situation where you might even consider hitting or doubling, it's too rate and too much of a longshot to actually do.
But with a total of 20, you're going to have a good chance of winning anyway.