A familiar trope in super-hero comics (or indeed, in other forms of fiction and mythology) is that a character granted enormous strengths is also saddled with equally enormous weaknesses to balance out their advantages.
Sometimes these sort of weaknesses are implied by the power facts themselves: although a fire-projecting character can be assumed to be invulnerable to fire and heat, they might be very vulnerable indeed to water and cold-based attacks. Vice-versa, a cold-manipulating character might be more sensitive to heat/fire based attacks and environments.
Especially when the game mixes characters with godlike powers and those with more mundane abilities, it may be appropriate to require that an exceptional power or ability be paired with an equally restrictive limit or weakness that negates its effectiveness.
Likewise, it's entirely appropriate for a player to place limits on their own character without outside prompting to humanize the character, emulate the genre, provide further roleplaying opportunities, or just to be a compel-magnet.
For example, Emma envisions her character Miss Invictus as the traditional 'flying brick' archetype, and writes down a huge list of power facts including super-strength, invulnerability, flight, super-speed, super-senses, and energy-blasts. To balance this out, she also includes power facts making her vulnerable to certain radiation wavelengths and magic, both of which render her character powerless. Since the GM sees room for both weaknesses as coming into play in the game, they agree that these are good limits for the sort of game they will be playing.
Like all power facts, feel free to discuss which ones might be appropriate for your table with your group and the GM. Too many weaknesses with too few strengths can make a character unplayable, whereas the reverse could result in a character that is allowed to hog too much of the spotlight compared to her peers. This can be a balancing act, and you should be unafraid of making adjustments as you go if additional calibration is necessary as discovered in play.