How long is 'a few years'? Controlled environments shouldn't be necessary for unplugged drives, just keep them at or slightly below room temperature. I've had

How long is 'a few years'? Controlled environments shouldn't be necessary for unplugged drives, just keep them at or slightly below room temperature. I've had three external hard drives for 7 years, and none have stopped working. I have one, and keep two somewhere else (office, family). I connect one for a few hours every week/month to update, then leave alone until needed, or rotated with one elsewhere.