How to dress newborn at night in the heat?

Little one is due in 5 weeks which puts us in the middle of summer. It's also supposed to be really hot throughout summer (including now). Currently my/baby's room is averaging between 23-24 Degrees Celsius at night with window and door open with the blind closed. Being a first time mum who won't be using a grobag, my question is this: what should I dress baby in once he arrives if this temperature keeps up? Google gives so many different answers with some saying at 23/24 Degrees to just use a short sleeved vest, others saying just a long sleeved vest, others saying just a sleepsuit and others saying a short sleeved vest and sleepsuit (none with any blankets). Any advice is welcome as I want to be as prepared as possible!