The card doesn't actually say to lose health - it just says, "Before the encounter, lose
But you are correct in that it would be consistent to change "lose" to "take" in these places:
Fire Elemental Flames
Lich's Tomb Blade Storm (twice)
Yeti's Cavern Freezing Winds
Rogue Daring Gamble (both sides should say "Take
" - best I could do for an hourglass)
Paladin Armor (twice)
The Boss Fight card should change "lose" to "spend" says "If you lose
due to a skill (ex. Dodge), no effect."
Although I have to admit that I don't understand that last part, since I don't think that any skill (including Dodge) requires spending time. Archer Kiting already treats Boss Fights specially.