Can I boil off chlorine? Does it evaporate quickly at high temperatures?
Yes, solubility of chlorine decreases drastically as the temperature rises, and it's almost insoluble in boiling water.
That's also the reason why in the areas where tap water is chlorinated, it advised to boil it before drinking.
Data from [1, p. 8]:


Figure 5. Solubility of chlorine in water, hy­drochloric acid (two concentrations), and so­dium chloride solutions (three concentrations) All percentages are weight percents.
In aqueous solutions, chlorine is partially hy­drolyzed, and the solubility depends on the pH of the solution. Below 10 °C chlorine forms hydrates, which can be separated as greenish-yellow crystals. Chlorine hydrate is a clathrate, and there is no definite chlorine: water ratio.

References

Chlorine: Principles and Industrial Practice, 1st ed.; Schmittinger, P., Ed.; Wiley-VCH: Weinheim ; New York, 2000. ISBN 978-3-527-29851-8.