The cage 40 degrees? What system are we talking? F or C?

40 C = 104 F

Either way 40 C or 40 F that snake is in trouble...

If 40 C get a lamp dimmer, or a new bulb (less wattage, 150 is way more than needed)

If 40 F get a new bulb

Your cage needs to stay 90 F (32.222 C) on the hot side and 80 F (26.667 C) cool side 24/7