Great question about the temps...... But First , I didn't want to forget about those that where asking about #2 and #3 bottles...... Any plastic bottle below #7 will have less oil, and polymers included in it, resulting in a thinner bottle that has a lesser life span dependent upon usage. For instance milk jugs are often#2 or #3 bottles, perfect for their applications, but not well suited for 100f plus conditions. Bottom line on plastic bottles is, any bottle #1- #7 that can be sanitized, hold liquid, will be usable, and safe for your process in not contaminated.
The temperature concern is as exactly as described by Hackwood. When you start to rise above 100F, the resins/oils in a thicker bottle (#7) will seep out very slowly over long periods of time if allowed to in liquid. Temps at or below 85F are not going to cause any affect to the bottle or liquid, regardless of #.