Whenever painting with encaustic, best practices suggest keeping the encaustic waxes from smoking (so, keep them to below 200-225 degrees (107 C) at the very highest. In addition, you should always have some sort of ventilation,
whether it is an open window (with or without a fan), and a source of fresh air such as a door open to the outside whenever possible. The less ventilation you have, the more diligent you need to be in keeping your paints closer to
185 F (85 C)