Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE head (age VARCHAR, head_id VARCHAR)
TABLE: CREATE TABLE management (head_id VARCHAR, temporary_acting VARCHAR)

### Question ###
What are the distinct ages of the heads who are acting?

### Accurate SQL ###

SELECT DISTINCT T1.age FROM management AS T2 JOIN head AS T1 ON T1.head_id = T2.head_id WHERE T2.temporary_acting = 'Yes'