I noticed you got only a limited answer, so I'll share my reaction.
I don't know. This doesn't sound related to Information Security, and I'm not sure you can expect people on this site to have relevant expertise. That said, I'm not sure. I'm not convinced it is off-topic for the site. I'm not sure it should have been closed for that reason. If the question was otherwise suitable, I would consider voting to re-open.
However, right now it is subjective and largely opinion based. It asks "What is the best way to...?" Generally, this wording makes it hard to evaluate answers and pick a single correct answer, so it makes the question not an ideal fit for this site. (I realize this is highly counter-intuitive. For what it's worth, it tripped me up when I first joined StackExchange.)
As a result, I think closing this question was appropriate, and as it currently stands it is not in a shape suitable for a vote to re-open.
If you would like to see the question considered for re-opening, you can edit the question to improve it. Here are the edits I would recommend:
Instead of asking for "the best way", it's usually better to list the evaluation criteria you will use to evaluate answers. Are there some hard requirements? Some metrics? What options have you considered and rejected? This will help you craft a more focused, objective question.
For instance, maybe you aren't looking for the "best", "cleanest" way to defend yourself. Maybe you are just looking for a practical way to defend yourself. If so, ask for that.
Also, try to stick to one question per question. Right now you ask two questions: What's the best way to defend yourself? Would an IR light work? That's two questions. Admittedly, they are closely related, but you might do better to focus on just one, or ask them separately. Right now, I can imagine an answer that says "No, an IR light wouldn't work (for such-and-such reason)."
Lastly, show your research. Keep in mind that, as the help center states, "IT Security Stack Exchange is for Information Security professionals". The more you show that you have done detailed research, and can show that there is technical depth to the question, the greater the chances that it will be suitable.