Software company founder John McAfee was taken to hospital on Thursday after being denied political asylum in Guatemala.
McAfee told The Associated Press that he suffered chest pains overnight but didn't believe he had a heart attack.
A government doctor said he appeared to be suffering from high stress.
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The district's director of homeland security has said officials are planning for 800,000 to 900,000 people to attend the ceremony.
The Supreme Court is set to decide on whether disabled travellers are legally entitled to have priority use of wheelchair spaces on buses.
There will be some brightness, with the best of the sunshine towards the south and southeast where it will again be chilly.