Sleep arrangements for a 4-week-old kitten

I am currently housing a 4-week-old kitten in my main bedroom. My senior cat, Vera (9yo tortie, arthritis), sleeps on the floor near the radiator. The kitten is in a laundry basket on a bookshelf, about 3 feet off the ground.

I am observing two issues:
1. Vera hisses when I move the kitten's food to the shelf.
2. The kitten is cold at 4 AM, despite the basket.

Where should the kitten sleep to ensure safety from the senior cat and minimize disturbance? I need a location that allows me to monitor both without disrupting Vera's rest.

Put the kitten in a closed room. See quarantine setup for new arrivals. It reduces the scent marking conflict immediately. My Luna hisses at every new scent, so isolation is the only way to stop the noise.

I considered isolation, but the kitten is not fully weaned yet. I need to bottle feed at 4 AM. A separate room means I am walking across the house in the dark, which risks waking Vera if she is on the floor near the door.

Also, the kitten's temperature drops to 98°F at 3 AM. Is the shelf height a factor in the cold?

What is the ambient temperature in that room? If it is below 70°F, a 4-week-old kitten will struggle to thermoregulate.

Check safe heat sources for kittens for protocols on heating pads. Do not use a heating pad directly under the basket without a barrier. The kitten must be able to move away from the heat source.

If Vera has arthritis, the floor is bad for her joints. See arthritis-friendly spots for seniors.

Move the kitten to a low, padded bed on the floor, but in the opposite corner of the room from Vera. Use a baby gate or a heavy piece of furniture to create a physical barrier. This keeps the kitten warm (floor drafts are worse than air drafts) and prevents Vera from lunging.

Just keep the kitten in your lap. I did this with Ollie when he was small. It is high maintenance, but it solves the cold and the hissing at once.

See feeding schedules for weaning kittens for how often you actually need to feed. You might not need to wake up as much as you think.

Lap sleeping is not sustainable for a 4-week-old who needs to eliminate every 2 hours.

I tried the baby gate idea from @greg_walsh. Vera stopped hissing after 20 minutes because she could not see the kitten. However, the kitten still got cold.

I am now using a heating pad on low, wrapped in a towel, under the basket. Is this safe? See safe heat sources for kittens again. I want to ensure I am not creating a fire hazard.

A heating pad wrapped in a towel is generally safe if it has an auto-shutoff.

The hissing is likely territorial. See managing hissing during introductions.

Your current setup (shelf + barrier + heated pad) is the most logical compromise. Monitor the kitten's temperature hourly for the next two nights. If it stays above 99°F, you have solved the problem.