Being on a modern E-Bike in 39C is definitely way more comfortable than walking. You can adjust the power settings so you barely have to touch the pedals to move, it's less effort than walking, and you'll be traveling at up to 25 km/h so you'll get some air cooling you wouldn't get if you were just walking.

I've ridden mine in up to 35C and it's like stepping into an oasis compared to standing still in that temperature, more so if you wear clothing like loose fitting cotton clothing that benefits from the increased airflow.