So this was bothering me.....I had to do some research. This probably belongs in Indoor lighting or growroom set-up.....meh.

Barloworld Scientific:

Temperature Resistance

Pyrex® borosilicate glass has excellent thermal properties due to its high softening point and low coefficient of expansion (3.3 x 10-6 K-1). The maximum recommended working temperature for glassware manufactured from Pyrex® borosilicate glass is 500°C (for short periods of time only). Special care should be taken at temperatures above 150°C to ensure that both heating and cooling are achieved in a slow and uniform manner (see "Care and Maintenance of Laboratory Glassware" section).
150° C = 302° F

Typical 400-600w bulb temps: up to 700° F

Wow. Lucky day.