Hair is a form of insulation, so it is worth a try to cut it. What you will most likely find is that shorter hair makes little difference in lowering body temperature if the environment is above normal body temperature.
Home improvements can reduce the amount of heat in the living environment. The type and condition of roofing and insulation play a part. If there isn’t a central AC system or one that effectively works, a window AC unit can be invaluable. Opening windows at night if the outdoor temperature is low enough will help cool off an abode, especially if a crosswind can be created. If not, a floor fan can help. The type of window blinds can also make a difference.
Wet hair, clothing and even bathing in cool water only last briefly. Cooling the body’s inner core where there is more heat is more successful. Consider consuming foods that are chilled. Eating grapes, bananas or yogurt that have been stored in the freezer for an hour or so are healthy options. Refrigerated foods can also help.
Sitting on ice cubes or using any other form of frozen treatment to cool the outer body can be harmful to the skin unless wrapped appropriately in a protective cover like a towel and with limited use.