Toddler low grade fever for 2-3 days

My son is 21 months. He and his sister have both had a cold/cough for a few days. My son has consistently had a low grade fever since symptoms started. It’s usually around 99-100. He’s been super groggy he napped 3 hours yesterday which is long for him and today he woke up from nap after like 2 hours but was just laying there super groggy not wanting to fully wake up. When I went to get him up his temp was 100.1.

Is it normal for a low grade fever to last that long with a cold?