Hi I am new here and planted a Meyer lemon tree in our spring(Western Australia). My question is we are having one of our hottest starts to summer and I am wondering is there anything I need to do to cool the plant. We have had 3 successive days over 41C (105F). Will be cooling down for a few days 33C (90'sF), Then back to the heat. Is this fine or should I add shade the tree ?

Thanx in advance

When the temperature rises over 100 F the meyer lemon grows slowly or maybe not at all. Damage should not be a problem though unless it is suffering from drought. Temperatures between 80F and 100F are best.

Firstly, I agree keeping the plant hydrated is the most important factor,
and that 40'c in itself shouldnt be a problem. If you are getting 40'c and zero humidity and hot dry winds and direct sunshine all day, which is what we have in Victoria, some extra care may be needed.
It is best to water before it gets hot, to hydrate the plant to carry it through the day. Any shade you put up is going to drop the temp, and evaporation rate which will help. Also be aware of high night temps, as 20'c plus at night is going to carry on the heat effects longer. ie 40'c + 25'c night + 40 +25 at night is closer to three very hot days.
As you have only planted the tree in the last few months, now being mid summer in Australia, you will need to give it some extra attention at first.