That is probably too much heat in a single spot. Several smaller bulbs will generally be better. See if they can let you test the bulb, to give determine if you can get enough standoff distance under your blankets to not burn or desiccate your trees. Also, the bulb themselves get very hot, so would need an appropriate mount to not possibly cause a fire.

Old school incandescent bulbs produce equal heat, but more gentle distribution. They still sell them (I think 40w is the max) at pet stores for keeping reptiles warm. For larger trees, a small space heater fan set to lowest setting would would well also since they circulate the warm air.

Thanks, I also believe the halogen would be hot. I was also thinking of putting the halogen outside a tent structure letting it shine on the tent structure maybe warming the inside of the tent. Concerned about fire though. Thanks for the advice about the bulb at the pet store. Praying this entire event will go away . Carol

If I could I would definitely look to put the lights inside, so you have the non-projected heat from the light also inside the structure. You can easily string several incan lights under the tarps to provide some light as well as heat with equal wattage. Also, keeps the electrical under cover, except the extension cords of course. Good Luck!

The flood lights are better; 250-watt red heat lamps would be more efficient. Keep in mind that any heat source outside of the protective structure (blanket, tent, etc.), will be mostly ineffective in wind.