If you are in trouble of any sort, one way to send a distress signal is to send out a SOS. The spelling out of SOS in morse code is ... --- ... or dit dit dit dash dash dash dit dit dit. So if you are in trouble of any kind, whether it be stranded somewhere or stuck in the jungle, this simple message could help you.

How do you send this out?
You could send out this message in various ways.
If you have a radio of any sort, you could blast it out in the hope someone is listening.
If you have a mirror you could flash the light at passing ships, planes or even cars if they are in the distance.
At night, you could signal it in a similar fashion to passing ships, planes or cars.

Dits are short burst, so if you have a flash light, it would just be less than a second
Dashs are longer bursts, so with a flash light, they would be one to two seconds
Spacing between each letter should be less than a second
Spacing between each word should be around one to two seconds