100,000m deep, assuming 1atm at the surface and comparable-to-earth gravity, will be a spectacular pressure. If ice forms, it will quickly melt again at very low temperature. Your character's escape bathysphere must be made out of triply-reinforced unobtanium, or it will be crushed by that pressure, too.

For reference the OP previous asked something similar on Physics SE and the question and answers are here if they're useful to anyone answering.

Unobtainium sounds good in Dutch too: Onoptanium.

@DescheleSchilder That fish biology is so different to us. If your characters are plain Homo sapiens, our world record in keeping humans alive is a mere 10,000m deep en.wikipedia.org/wiki/Trieste_(bathyscaphe)

Do you really mean "viscious" aliens? Is that a portmanteau of "vicious" and "viscous'?

@Pcman Its no portmanteau...:) Its a spelling mistake. I mean vicious... like Sid Vicious... It could be a nice new word though! Meaning vicious viscous.

Tip for your writing: SI units named after a person have their symbols capitalised but are lowercase when spelt out. So, 'K' or 'kelvin' but not 'Kelvin'.

@Transistor Ah! Allright. Thats a good point indeed! Writing is also about spelling, so. So I should write that lord Kelvin's temperature was 37 celcius? Or degrees celcius?

@Transistor Or degrees celcius? Or just 37 degrees? Or just 37?

Not quite. Since "lord" is his title it is a proper noun and gets a capital 'L'. That makes it, "Lord Kelvin's temperature ..." You could say, "Lord Kelvin's temperature was 310 kelvin" (or "310 K" or "37 degrees Celcius" or "37 °C"). Note that Celcius is not an SI unit and it is capitalised when spelt out.

@Transistor Thanks for this mini-lecture! Very enlightening. I never will make a mistake regarding that anymore.

@DescheleSchilder I would suggest you ask that of on the Physics Meta SE, it is quite inappropriate to ask it here.

@StephenG I cant. Im suspended (luckily so) for bad contributions so I cant ask it there. I was just curious. Never mind!

@Transistor, celsius is an SI derived unit.

@SolomonSlow, you are correct except it is capitalised - Celsius.

@DescheleSchilder are you sure your ocean is 100km deep? that is insanely deep, and probably not physically possible. it would be like saying "on my hypothetical planet there is a mountain which is 500 km tall" - it just makes no sense.

@Fattie Mountains maybe make no sense. But there are oceans on Earth almost 11 km. deep. I dont see why 100 km is not feasible. If the water is hot enough. What holds an ocean that deep from forming? 100 km high moutains maybe?

You got suspended on Physics for opening new questions over and over. That wouldn't have happened if you had edited your original question to fix the flaws, and then flagged it for re-open. However I think what really got you in trouble was being cheeky, as you were to Transistor above.