well, I didn't want to make it hot & cause some kind of reaction with the plastic in the bottle. it's not made for hot drinks I don't think. just warmed it so it wasn't as cold as the filtered pitcher water on my counter, so that it would take longer to freeze. and I only sipped it to coat my throat, wasn't really like drinking a hot cup of coffee. but some riders do carry insulated bottles of hot coffee on their rides