Strong mind and a strong body
I’m already pretty warped now, so no prep necessary. 
But what if humans are just brains living in the Matrix by then? Or if we’ve engineered ourselves so far away from baseline that modern humans would call them cyborgs/robots?
You’d wind up looking a little like the guy in that Twilight Zone where he steals gold, does a Rip Van Winkle to sleep into the future, then kills his friends over the gold. When he tries to sell it, he discovers that man-made gold is now cheap and plentiful.
Since I’ll be dead within seconds I won’t bother with any preparation. I don’t really want to take the risk today, but given not all that much time the risk of dying won’t make much difference to me so maybe a space-suit (odds are I don’t end up on land much less a hospitable environment). And maybe a towel.
You guys don’t understand how far into the future 100 million years is.
One thing I’d want, along with the spacesuit and survival all terrain vehicle, is a suicide pill. You don’t know WHAT is going to be at the other end. A quick painless death might be the best you could hope for.
You only think you do, most likely. You know, abstractly, that it is a very long time but I doubt you have a better handle on just how long than anybody else.
It’s kinda cute that some people are concerned about pollution contamination or obesity in the world 100 million years from now. Like as if the story arcs during your tiny little blip of existence will continue unabated for 100 million years.
I would prepare by doing lots of yoga and stretching, so I might be able to kiss my ass goodbye.
Of course you’re right. I don’t have an intuitive grasp of such things, I just know that the amount of time we’re talking about here takes us so far into the future that it’s comparable to going back to the middle Cretaceous, the time before mammals became the dominant life forms on land. So speculation about what “people” of that time will be like are just silly. If robots ever conquer the world, it’s either going to happen instantaneously on the geologic time scale (ie within a few hundred thousand years), or it’s never going to happen.
I agree that I don’t have an intuitive “feel” for how long a thousand years is, or a million years, any more than anyone else. But I know a lot of facts about how long ago certain things happen that make useful reference points. So 1000 years ago was the middle ages. 10,000 years ago was the end of the ice age and the very beginnings of agriculture. 100,000 years ago was the beginning of anatomically modern humans. 1 million years ago we had Homo erectus. 10 million and humans, gorillas, and chimps were a single species of ape. 100 million years ago we’ve got dinosaurs ruling the earth and humans and all surviving placental mammals are descended from one species of tree shrew. 1 billion years ago is before multicellular life. 10 billion is before the formation of the Sun, and there’s no larger order of magnitude because time seems to have began something like 14 billion years ago.
So by keeping these sorts of timescale in mind we can sort-of get a feel for the amount and magnitude of time we’re talking about. Not by directly understanding how long this is, you’re right that’s impossible, but by analogy and comparison. Just like it’s hard to understand just how far it is from Los Angles to New York, 2500 miles is just a number. But we can get some idea by putting into terms we do undersand, if you could walk 25 miles a day it would take you 100 days to walk that distance. I’ve walked 25 miles in a day a couple of times, and it was a lot of walking. No idea how you could keep that up and find enough to drink, enough to eat, and a dry place to sleep every night. And this is assuming no injuries, no hostile natives, no need for detours.
Anyway, the point is that we can get a handle on numbers that our brain can’t really understand intuitively other than “really big” by comparing it to things we already know. That’s all I’m trying to do with the time-scale here.
My first comment was that at 100 million all bets are off regarding what things are like with humans.
On the other hand, one of the fascinating things about comparing today to 100 million years ago is how many things actually have NOT changed. Humans may have been shrews and birds were wingless and full of teeth, but crocs and sharks were remarkably similar. The atmosphere would be breathable, the food would be edible, the temperature survivable.
In fact, it’s human intelligence and technology that makes it such a guarantee that we’ll be different in the future. From a purely naturalistic standpoint, once a creature finds a stable niche, they may remain stable themselves.
As other’s have pointed out the problem is that you are, for all practical purposes, essentially landing on a different planet in 100 million years and other than than gravity and the sun there will be few common referents. Intelligent life if it does exist as a linear evolution from today, and has not destroyed itself or gone extinct, will probably not be biologically based and will not be ready or able to cater to your human needs. You will be the tree shrew and your inherent “rights” as the alpha sentient creature where you came from will not exist. You will be dead or a laboratory specimen or a zoo animal in short order.
You have no idea what you’ll be stepping into. There could be a mutant germ (a la Andromeda Strain), maybe extraterrestrial, that dissolves your suit in 10 seconds and then goes to work on your lungs. There could be something else that can’t be de-contaminated off your suit if you come back, and thank you very much for infecting our present world with it, possibly terminally. Sorry, once you go, I ain’t bringin’ ya back. You might be able to send us some telemetry? That would be nice, thanks.
Would microbes and viruses in a really distant future (or past) likely be more dangerous to me than those existing today? Wouldn’t they be more like cat’s flu: completely harmless, as they have evolved to exploit totally different life forms?
I’ll want to take a pair of chaps to ride one of the domesticated t-rex’s that future human immortal clones will have created through genetic resurrection so they can fight the invading repitilians.
Oh, and a multitool and a freakin’ sharp samurai sword. Cause you never know what you need, and I look really cute with a sword, high heeled boots and a leather bustier.
Given my amazing imagination and decades of military experience (because I come from a warlike planet while humans of the future will be passive peaceniks) I expect to conquer the replitilans through dropping a weapon into the access port that leads directly to the center of their planet destroying laser beam, and be crowned queen within a week.
After than I will undergo a transfer of my brain into an immortal body and spend the rest of my life until the end of time, instituting crippling taxes to build and furnish my impressive palaces on millions of planets.
You know, if the hero of this story was a guy, I could find a publisher.
^ Do you really think a guy in a leather bustier and high heeled boots would sell? Well, maybe for the novelty factor.
BTW, would your high-heeled boots also be thigh-high, 'cause I can get behind that. 
Pretty racy stuff for a dean’s wife, I must say. 
I’m bringing a Beanie Baby.
Can you imagine how rare those would be? I’ll make a fortune.
Side note, Cracked did an interesting thought experiment about the end game of immortality. They posited that you basically have a 100% chance of being trapped somehow (like in a building collapse for example) for a near-eternity, waiting for the sun to explode.
I guess the end-end game of immortality involves hurtling through space after your solar system is gone, many light years from the nearest star, going completely insane from boredom.
Thanks for the tip! I’ll also institute really really strict building codes, and not go into underground facilities.