Thermal is another term that you're familiar with, although, you'll commonly think of Long John underwear or some other type of warm pajama worn underneath clothing in the northern areas of the globe because it can get quite cold. Thermals are commonly used as insulation in cold temperatures but they've been broadened out to include thinner styles of shirts that still retain the waffle weave. There isn't any one way to make a Thermal shirt but nowadays they're a fashion trend because they can be worn in the cool spring time months or in the colder winter months with layers for added heat insulation.
Don't forget that a "Waffle Thermal Shirt" must have the honeycomb or box-like weave otherwise it's just a regular shirt. A thermal insists that it's medium to heavy weight cotton so if you find a thin shirt that has the honeycomb weave, it's most likely just a waffle shirt not a Waffle Thermal. There may very well be thermal sweaters as well but it's not common. Before winter comes, you should get yourself a few Waffle Thermal shirts to layer up or to keep mildly warm in the cooler spring time. It's your choice.