My tooth is still sensitive to temperature after root canal treatment. Is that normal?

Yes, some discomfort or tenderness when chewing for a few days right after root canal treatment is a normal part of healing, because even though the nerve was removed, the tissue around the root (the periodontal ligament) takes time to settle. Reacting to hot and cold, however, is unusual in a tooth whose nerve has been removed, so it may be a problem with the neighboring tooth or an additional canal that was not found. If the discomfort lasts more than 2 weeks or gets worse, you should come back for a re-examination.