My new tattoo is very red it feels hot and is very sensitive what should I do?

Could be a skin reaction to the ink. See a dermatologist.

If it is very recent as in 1-2 days that is normal. If longer than you need to see a doctor. Did you get your tat done at a salon that is registered with the health department or in someone's basement? You run the risk of infection etc when you get it done by someone that does not follow proper procedures.