The most obvious dangerous type of flops are three cards of the same suit when you do not have one of it.
But besides that beware of a flop that is coordinated or even worse coordinated and suited. These boards are dangerous even when holding a hand like pocket aces or kings.
With a board like J,10,9 or or 7,8,9. For example, with the board of 7,8,9 if a Q,J,10,6,5 or 4 hits there could be serious problems but on top of that there are already made straight possibilities.
Another problem with these type of situations is that someone with a strong hand like a set or two pair is also going to be worried about all the draws and often will push very hard on the flop. And so will someone with a big draw...so how will it be possible to tell the difference?
Not to mention even if they do have just a draw as long as it is not a gut shot they will be just under a coin flip against only one pair, even a pair of aces. Or even possibly a favorite if they hold a flush draw with an open ender.
And to make matters even worse if they have a made straight, with only one pair you will be only 2 to 5% to win which is just a little bit better than drawing completely dead!
The best way to avoid being put in this dilemma is to raise it enough preflop in order to give incorrect odds to your opponent before they have a chance to outflop you. If you do this you can pay off better hands once in a while and still come out ahead in the long term
Basically this is the same plan (to raise the heck out of it preflop) but with the possibility that nobody raises and everyone sees a super cheap flop. Where you must revert to strategy for playing just one pair post flop.
Or just plain folding when the pot is small. It is appropriate to fold one pair even if they're pocket aces or kings especially when one or more players show strength or interest in a min raised pot with a coordinated dangerous board.