When is a market too hot to buy into?

[Brian Bleifeld]

Hello all part time real estate investor and full time CPA.  Looking at Houston and Texas housing prices become so heated in the last four months.  Looking for advice to calm my investor clients who are getting very aggressive when offering on properties.  What guidelines do you guys use to make a pass decision due to a hot market?  Is it a certain % up in a year.  Do appraisals have any sway with your decisions.  Most of my clients are long term hold investors.