Are infrared heat lamps safe for me and my snake?

[prairiepanda]

Are you sure you're using a thermostat and not a rheostat? What you're describing sounds like a rheostat, which just sets things at a certain power level regardless of temperature. They are often cheaper than thermostats, but I'd recommend you upgrade to a thermostat in the future. Thermostats have temperature probes on them, so rather than setting a power level you set the desired temperature, and the thermostat either adjusts the power level or turns the heater on/off(depending on the type) in order to maintain the temperature you have set. That way you won't have crazy temperature fluctuations when your A/C is turned on or off, as the thermostat will ensure a steady temperature in the enclosure.