In the winter, heating systems often dry out the air much more than we realize.
The humidity in my house was down to about 30% and it was giving my son nosebleeds--so I got a humidifier .
It helps to keep the chams' air humid also.
Mine is a cool air humidifier, so it isn't making the electric bill skyrocket.
I try to keep my Jackson's humidity above 70% and up to 80-85% is fine.
You don't want it to be a constantly wet environment either, as that encourages respiratory infections to set in.
I avoided foggers and the ultrasonic humidifiers because I worrird about the potential for RIs to set in.
Perhaps I am wrong on the ultrasonics and foggers but I didn't want to chance it.
The males tend to have a sleeker build, while the females look a bit rounder overall--and yes, they are smaller than the males.
Final size and weight is variable, but my male Jackson's Karma had been 115 grams. He was not fat at all.
Even though she was a bit too fat, my female Snowflake was only about 70 grams.
The incandescent bulbs are just regular ones like Philips or Sylvania that you'd use in a regular lamp.
Maybe the wattage is too high or it's a halogen bulb and is brighter.
For mine a 40 watt bulb is good but the basking temp it provides depends on how far from the basking spot it actually is and what the room temp is.
Your Jackson's do need the warmth to digest their food and metabolize the nutrients properly.