He got sick and was not able to put on the ihram garments

If the pilgrim enters ihram wearing his regular clothes for some reason, such as cold, sickness, and the like, then he is permitted to do that according to sharee’ah. What the one who wears sewn garments has to do is to fast for three days, or feed six poor persons, giving half a saa’ of the local staple food to each person, or sacrifice a sheep that meets the conditions of udhiyah (sacrifice). The same ruling applies if he covers his head. Fasting may be done in any place, but feeding the poor and sacrificing the sheep must be done in the sanctuary of Makkah. 

And Allah is the Source of strength. May Allah send blessings and peace upon our Prophet Muhammad.