I have built a brooder box from plywood. It measures 4ft long 2 ft wide and 2ft tall. It is in a non heated room. Under the heat lamp which is a 250 watt infra red bulb the temp gets up to 99 degrees plus. About 12 inches from center of the light it is between 85 - 90. The light is on one end of the brooder box. Is this ok?