My heat lamp went out today for my chickens. Local agway and tractor supply is closed for new years, so i have no way of getting a bulb. I thought i had more in my barn but it turns out I was didn't. Now I know always keep stocked up with bulbs. The chickens are 5 weeks old, fully feathered. The barn is in the 40's. Will they be fine for the night? We are in NJ.