If there's a limit to cold, but no limit to heat, doesn't that mean that the universe will get hotter ..

...and hotter to infinity?

Kind o' like hell ?

This is a serious question.

The real universe appears to behave like the theoretical universe described in the Big Bang theory:

-- the amount of total energy appears to remain constant;
-- space is expanding;
-- the energy density (a.k.a. temperature) is decreasing in a monotone fashion (mathematical term)

Because there is a limit to cold (equivalent to an energy density of 0 over any finite volume), the actual temperature should decrease in an asymptotic way (it should get closer and closer to zero, without ever reaching it).

If you use the theory backwards, it would appear that the temperature, in the past, has no absolute limit. It could have been as hot as any number you wish to make up. However, in practise, we no longer understand how things work when the temperature is above
141 683 300 000 000 000 000 000 000 000 000 K
Although this number seems large, it is still exactly 0% of "infinite" so that space COULD have been expanding forever before the moment we call the "Planck Time", 13.7 billion years ago.

At that temperature (and above) we do know that matter could not exist. In fact, we know that the individual forces could not exist (even the quarks could not exist, therefore no bosons and no baryons).

Hell's temperature is supposed to be designed to inflict pain. Therefore, it has to be lower than 150 C (roughly 420 K). In practise, I would guess that hell cannot be hotter than 400 K. Higher than that and the heat breaks apart the carbon chains that are necessary to maintain the nerve tissue that would bring the pain information to your brain.

I plan to bring a bottle of water in case I get thirsty. You should do the same. (see additional number 3, at the end)

Except for the above sentence, this is a serious answer.

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Additional answers:
1) no