Matt. 24:29 says that immediately after the end of the Great Tribulation the Sun will be darkened and the Moon will not give it’s light. How can that happen without everyone freezing to death?
Remember, even though God created light on day 1 of the creation (Genesis 1:3-5), He did not create the Sun and Moon until day 4 (Genesis 1:14-19). So there was light before there was a Sun and Moon. That means the same could be true afterward. And like it was with the creation, only light is mentioned in Matt. 24:29. We have to assume that heat accompanies light.
According to Rev. 21:23-24 the source of light for Millennial earth will be the New Jerusalem.
“The city (New Jerusalem) does not need the sun or the moon to shine on it, for the glory of God gives it light, and the Lamb is its lamp. The nations will walk by its light, and the kings of the earth will bring their splendor into it.”