This reminds me of a paper [1] where they find that... "In the redshift range 100<(1+z)<137, the cosmic microwave background (CMB) had a temperature of 273-373K

This reminds me of a paper [1] where they find that... "In the redshift range 100<(1+z)<137, the cosmic microwave background (CMB) had a temperature of 273-373K (0-100 degrees Celsius), allowing early rocky planets (if any existed) to have liquid water chemistry on their surface and be habitable, irrespective of their distance from a star." [1] https://arxiv.org/abs/1312.0613 https://arxiv.org/abs/1312.0613