iceland bubble pools / hot springs

i have a bit of a paranoid question about the bubble pools / hot springs in iceland.
are they all safe to go in? if a hot spring is nice and warm and seems like a great idea, is there a chance it will spontaneously heat up and cook me alive like a lobster?
are there signs posted as to which hot spings are safe and so on or is it a try at your own risk kinda thing?

maybe silly but better safer than sorry ;)
thanks!

they are not all safe to go in, and since many are in remote areas, they don't all have signs on them.

The ones in tourist areas that aren't safe are generally posted (like at Geysir), and the ones that are safe in tourist spots are usually full of people (like Landmannalaugar). Outside those, hot springs are tucked all over the country but I think you probably need to have GPS/local info to find them (there was a guide book posted recently but it's all in Icelandic). The ones that are too hot generally LOOK too hot- they're bubbling, they're extra-steamy, they've often got lots of crazy algae and mineral buildup, and if you try to touch them it's pretty obvious that you don't want to immerse your whole body in them.

When you find one that is the right temperature, I've never heard of them heating up so quickly that they scald someone, so you'd have time to scramble out quickly. Now you just have to figure out where to find them ;)