It's all I've used camping for a number of years.  One on a string in my tent, one in my small "personal" stuff sack with meds and such.  Scout camps of course have a Coleman propane lantern in the site and this past Christmas my son gave me a head lamp - which I used to read a book but not generally.  I've had same "toys" for over 5 years and they seem just as bright  - at 100 F or -15 F.