Not a specific brand but style of electric heater. I prefer the oil filled ones. They make zero noise and safer because they don’t have an exposed heating element that can catch things on fire by coming in contact. The one have has a temperature setting and a clock that can be programmed to turn itself on/off at designated times. Cons are they take a while to heat up and are a bit larger. Mine is tall and thin, looks a bit like a boiler radiator. The big hardware chain stores sell them, I’d expect to pay around $100.

Looked it up on home depot website. They have a lot to pick from. Some are cheaper but with less features https://www.homedepot.com/p/NewAir-Portable-400-Watt-Electric-Oil-Filled-Silent-Slim-Fit-Design-Under-Desk-Heater-with-Energy-Efficient-Operation-White-AH-400/205588528

Candles.

Class up the working environment with a room-warming candelabra.