I spilled very hot coffee on my upper thigh and it's very red and now has a few blisters. should i see a doctor?

Yes please: It is important that you visit a doctor. A hot fluid burn can be deeper than you realize and it's important to have the right dressings applied from the outset to ensure good healing. The burn wound may also be infected and you may need antibiotic cover.

Water: Use lots of cool water. Second degree burn will be painful but will heal in 2 weeks. A bioclusive or tegaderm membrane on it will stop the pain and promote healing. Avoid antibiotics on the burn or by mouth. Do not bother with a Dr unless you know one with experience treating burns. Very few Drs do.

Second degree burn..: The blisters are what makes a burn second degree. Cooling the area at the time of the injury allows the area to stop burning. Then a protective dressing will prevent secondary infection. If there is any signs or symptoms of infection like increasing redness, pus, fever, chills, etc., you should see your doctor. If needed, there are doctors who specialize in burns that you can be referred to.