Don't you just love the phrase "Investigator's Brochure"?  It's an unusually colorful industry term that harkens back to a simpler time when printed brochures (and not the internet) were a primary mode of advertising. "Investigator's Brochure" and "temperature excursion" are evocative of travel during the days when you had to dress up to go on an airplane. 

In barely related news, the IB section of ICH GCP E6 R3, now named Appendix A, has also undergone some changes between the May 2023 draft and January 2025 final version of the guidance. Here we go:

• Section A.1.2, which describes Reference Safety Information and Risk-Benefit Assessment, includes two new requirements for RSI:  "This RSI should include a list of adverse reactions, including information on their frequency and nature" and "This list should be used for determining the expectedness of a suspected serious adverse reaction and subsequently whether reporting needs to be expedited in accordance with applicable regulatory requirements (see section 3.13.2(c))" was added after the first sentence.  This sentence had previously been included in section A.3.6 (b). 
• Section A.3.5 (c), which summarizes the Toxicology section of the IB, uses the terms "single toxicity" instead of "single dose"; "repeated dose toxicity" instead of "repeated dose";  "genotoxicity" instead of "genotoxicity (mutagenicity)"; "reproductive developmental toxicity" instead of "reproductive toxicity", "local tolerance" instead of "special studies (e.g., irritancy and sensitization)." "Other toxicity studies" was added.
• In Section A.3.7, Summary of Data and Guidance for the Investigator, italicized text in the following statement, "Guidance should also be provided to the clinical investigator on the recognition and treatment of possible overdose and adverse drug reactions that is based on previous human experience and on the pharmacology of the investigational product," was changed to "previous clinical and nonclinical experience," a minor but important correction.