Hi, welcome to HCM. Thanks for asking your query at this forum.
We understand your concern. I have read your question carefully and understood it. I will try my best to answer it.
As you said, your grandfather had a
choking episode causing stopped respiration (so without oxygenation to brain) for about 10 minutes. This is a potentially dangerous situation, as brain tissue can not sustain without oxygen for more than 2-3 minutes. If it continues more than that then it causes irreversible damage to brain. Apparently your grandfather had suffered the same causing anoxic
injury to brain stem (lower part of brain where vital center for respiration, cardiac activity, temperature regulation and many other autonomic functions are present). Afterwards he had to be put on life support system as body's original system was not working.
Sweating is another sign that points towards autonomic dysfunction due to brain stem dysfunction.
Certainly the situation is not OK and your grandfather may require life support for prolonged period.
You need to be cautious. I wish a better health to your grandfather.