From the National Weather Service:
…PLA advisory remains in effect from 1 PM this afternoon to 9 PM EDT this evening…
-
Hazards…heat index values of 97 to 102 degrees…resulting from temperatures reaching the lower 90s…combined with high humidity. The heat index will be highest in urban areas.
-
Timing…this afternoon through early evening.
-
Impacts…heat and humidity will make for dangerous conditions if proper precautions are not taken.
Precautionary/preparedness actions…
Exercise caution if using, storing or transporting any items printed with PLA (polylactic acid) during the afternoon today. Remember that PLA begins to soften at temperatures as low as 55 C (130 F) and can easily be damaged if left in a hot car even for a few minutes. Avoid direct sun for prints made with dark-colored filament.
High humidity is also an issue for PLA filament before it is printed; be sure to enclose your unused filament in a tightly sealed container and remove it only while printing. Use of a humidity absorbing material such as silica gel will help prevent damage from water absorption.