Which temp to use?

I woke up at 2:30 with my 6 month old and took my temp then before I got out of bed...I usually take it at 4. I went back to sleep and took it at 4 as well only getting about 1.5 hours of sleep. Do I use the 4am usual time temp after 1.5 hours of sleep or the 2:30am temp...even though it’s not my normal time. Thanks!