How to Avoid Being Sucked into a Transdimensional Vortex

1. Avoid standing near transdimensional vortices. They are dangerous and you are likely to be sucked in.

2. Avoid places that have transdimensional vortices or where one might suddenly open up and suck you in. These include, but are not limited to: ancient pyramids, (Mayan or Egyptian) Paleolithic stone circles, black holes, magical gateways, doorways to hell, and laboratories of evil scientists.

3. If standing near a transdimensional vortex is unavoidable (and sometimes that is the case), then whenever possible set up safety handrails and proper safety gates. Further protect yourself by strapping yourself securely to something weighty and secure in our dimension with a safety harness. At the very least, tie a rope around your waist.

4. If you are being sucked into a transdimensional vortex, try and throw someone else in first. Often, a transdimensional vortex will close once someone has fallen through to the other dimension. Whenever possible, try to throw in someone evil instead of someone innocent.

5. A last ditch effort to avoid plunging in, is to cut off the power supply to the transdimensional vortex. As any evil scientist or ancient high cleric can attest, keeping a transdimensional vortex open requires a great deal of energy. Merely remove the power, and often the vortex closes up.

Calvin's Things to Avoid: Peeing in the Amazon River

Let me introduce you to the Candirú, also known as the toothpick fish, which are parasitic freshwater catfish in the family Trichomycteridae. They are found in the Amazon River and have a reputation among the natives as the most feared fish in its waters, even more feared then deadly piranha. They are eel-shaped and translucent, making them almost impossible to see in the water.

Toothpick fish are small fish. Adults only grow to around an inch in length with a rather small head and a belly that can appear distended, especially after a large blood meal. They have short, sensory barbs around the head with short backward pointing spines on the gill covers.

The Candirú lies in wait at the river's murky bottom, searching for its next host by sniffing the water for the expelled chemicals urea and ammonia from the gills of other fish. Coincidently, these are the same chemicals found in human urine.
It is believed that they enter the human urethra when it is expanded during urination and lodge themselves in the penis to feed.

Owch.
There was a reported case in which the victim claimed that the fish jumped and lodged itself in him while he was urinating in thigh deepwater.
Yikes.
I have decided to stock my swimming pool with Candirú. This should be an effective method to keep my guests from peeing in it during my next pool party.