So how hot does burning tobacco get? And when acrylic start to melt?
"The temperatures produced when tobacco was burned in pipe, cigarette, and cigar smoking have been measured by a calibrated thermocouple.
Temperature of the combustion zone in a pipe was about 500° C. (variability, 380°–620° C.). The maximal temperature was thus relatively low, but the heat spread over an extensive area outside the actual glow. Because of this, strong dry distillation took place, and the corresponding fractions from the evaporating substances escaped into the smoke without being pyrolyzed. With a cigarette, the situation was found to be quite different. The temperature was high, averaging 650° C. (variability, 470°–812° C.), but over a very limited area. The amount of dry distillation was slight, and the low and middle fractions were burned more completely. No essential differences could be noted among the different brands of cigarette studied."
http://cancerres.aacrjournals.org/content/16/6/490.abstract
500 C = 932 F
"Q: Will acrylic melt?
A: While acrylic softens at higher temperatures, it does not actually melt until it reaches 320 °F (160 °C). Therefore, normal household use does not risk melting acrylic. Hot stovetop items should only be placed on an acrylic tabletop surface using a protective trivet or other padding, preferably with rubber cushions. As a safety precaution, never place acrylic directly on or next to an open flame or hot surface."
https://www.plexi-craft.com/acrylic-plexiglass-lucite-clear-plastic.html